Unless the afterlife has wifi, I can presume that you’re alive and reasonably well if you’re reading this post, so I’m going to assume you’ve been successfully breathing for some time. You get enough oxygen into your blood to support your physiological requirements and power your limbs, organs, andmuscles. You know how to inhale, and exhaling is a breeze. You even know how to breathe through your nostrils like a champ. In other words, you can breathe well enough to live. What could you possibly be missing?

There’s a pretty good chance you aren’t breathing correctly. At rest, when sleeping, while running – you can probably breathe different and breathe better. Okay, you’re willing to accept that, as a whole, we’ve missed the mark on a host of supposedly mundane activities – eating, exercising, sitting, sleeping, standing, washing, heck, even pooping – but breathing? You’ve gone too far this time, Sisson. You’re firmly in the deep end. I breathe just fine.

Hear me out, and before you read any further, I’m going to have you take a deeeeep breath, so I can show you what you’re doing wrong. Don’t skip ahead; no cheating.

Put your right hand on your chest and your left hand on your abdomen. Take a big breath by inhaling through your nose or your mouth (whichever is most natural for you), slowly. Really fill your lungs, and note which hand rises more. Did your right hand move first and most, with your left hand lagging behind – if it moved at all? Did your shoulders go up? Did your traps rise like you were shrugging a couple dumbbells? Congratulations, you are a chest breather.

Now, procure an infant, preferably one with an exposed, protruding belly. Gender matters not. Got one? Great. Lay your infant on its back and watch how the kid breathes. Does his chest rise and rib cage expand? Maybe a little, but the bulk of the action is happening in the belly button region, right? That kid is “belly breathing.” In other words, he is using his diaphragm, a sheet of muscle located between the thoracic and abdominal cavities that (if you do it right) draws oxygen into the lungs upon activation. When it contracts, it moves down into the abdominal cavity, pushing the belly out, increasing the capacity of the lungs while lowering the air pressure, thus spurring the influx of oxygen. The external intercostals, muscles located between the ribs (flex your core with a finger on your ribs and you’ll feel the intercostals fill the gaps), also assist with respiration, but the diaphragm is the prime mover.

If your right hand rose first and most prominently in the previous exercise, you did not effectively utilize your diaphragm. Like the office worker with inactive glutes from too much sitting, you have an inactive diaphragm. Your synergist muscles – the helper muscles that assist the prime mover – are forced to take over. Without the diaphragm contracting and opening up the lower half of the lungs, less space is available for incoming air. Not only that, but according to some, the lower half of the lungs is also by far the most efficient at delivering oxygen; the bottom 13% of the lungs brings in 60 mL O2 per minute, while the top 7% only brings in 4 mL per minute. Chest breathing to the exclusion of diaphragmatic breathing (and that bottom 13%), then, is highly inefficient because it squanders added capacity and more effective tissue.

To really accentuate the inefficiency and help you understand how exclusively chest breathing limits your oxygen, let’s try a couple quick exercises. Stand tall and shrug your shoulders up toward your ears. Hold that position and take a deep breath. Or, rather, try to take a deep breath. You can’t do it. You can take in some air, but not a lot, and what you can take in sounds labored. There’s a big whooshing sound that just doesn’t feel right. It feels… weak.

Next, hunch over at the thoracic spine. Imagine you’re typing away at the computer (shouldn’t be too hard, seeing as how you’re probably reading this post on a computer) and let your chest cave in, your shoulder blades spread out, and your head droop forward. In other words, give yourself the type of terrible posture that millions of us sport each day. Hold that position and try to take a deep breath. It’s belabored, right?

Finally, suck in your gut. Flex those abs and flatten that belly. Inhale, and note how thin and ineffectual your breathing sounds and feels. Your diaphragm is pinned against your contracted abdominal muscles. It can’t go anywhere. It can’t do anything, and your breathing suffers for it.

These seemingly exaggerated scenarios actually are not. Realize that a good portion of people go about their day with tight traps, shrugged shoulders, rounded backs, and caved-in chests, constantly sucking in their stomachs as they try to breathe. You see them every day. You work with them. You might even do it yourself without realizing. It’s anything but rare. It’s normal! Alan Watts writes of this “normal” breathing as “fitful and anxious,” with residual air “always being held and not fully released.” Folks hold onto their air and simply pile more on top with the next breath, rather than breathe completely in and completely out each time. They get new air mixed in with the old stuff, enough to function but not enough to thrive. You’ll notice that the only time they truly expel everything from the lungs is when some stressful event elicits a massively audible sigh. That sigh clears everything out and brings a fresh supply of air back in, thus giving a boost of oxygen to the blood and helping us deal with the stress. In other words, most of us can’t even figure out how to breathe deeply in and out on our own to promote relaxation. We rely on our subconscious to do it for us.

I say, why wait for our subconscious to kick in? Why not practice proper breathing at all times and reap the benefits without having to wait till stress accumulates and does it for us? Why not do some diaphragmatic, or belly breathing?

You can do this lying down or standing up. To start with, I prefer lying down because it lets you really relax and focus on the movement of the diaphragm. Place your hands on your belly, or even lay a book with reasonable heft on your belly (this will give you something to brace against). Now, take a deep breath and let your belly expand as your diaphragm asserts itself. Your chest and shoulders may rise and your ribs may expand, but this is totally normal and expected as long as the belly moves first. Next, slowly exhale while tightening your core and contracting your abs. As the abdominal muscles contract, they’ll push the diaphragm back up. This will reduce the volume of the thoracic cavity, increase the air pressure, and expel the air contained therein. Continue to take deep diaphragmatic breaths for a couple minutes. Inhale three seconds, exhale six to ten seconds. Big, deep, slow, relaxing breaths.

Do you feel the difference? The relaxation? You might even fall asleep if you’re not careful. While there appear to be objective benefits to making this your default setting, like increased oxygen supply (great for general living and athletic performance), and I’ve already gone over how deep breathing can enhance a healthy lifestyle, the real allure of breathing with your diaphragm is simply using your respiratory as it was meant to be used. The benefits we get from breathing this way – like a reduction in hypertension – stem from eliminating the short, rapid, vapid breaths of chest breathing. We’re not getting “more” or “extra” oxygen; we’re just getting the amount of oxygen that our body “expects.” Nay, that it deserves.

But if my ways seems strange to my gymmates, theirs are equally bewildering to me: hours-long sessions spent wondering the floor, punctuated by short sets of preacher curls or goes at the hip-adductor machine.  How, I wonder can people work, day in and day out, so inefficiently?!  The answer, I recently realized, is practice.

And not just at the gym.  Studies show that the average American worker spends ten hours a day at the office, yet, after chatting with colleagues, surfing the web, and strolling to the water cooler, accomplishes just one and a half hours of actual work.  In other words, 85% of the time most people spend at the office goes completely down the drain.

I was initially drawn into our workouts by the brutal efficiency of the approach: such little time, such great results.  Which is why, marveling one day at the comparative inefficiency if the gym-goers around me, I started to wonder if what flows into the gym also flows back out.  If most people bring bad habits from work to working out, could I take good instilled habits in the opposite direction?  Could I Tababta my job?

At its heart, Tabata is simple: eight brief intervals of 20 seconds of very intense effort, separated by an equal number of even briefer intervals of rest, 10 seconds.  As twenty seconds of job productivity seemed slight even by my procrastinatory, distraction-prone standards, I decided to stick with the idea but adjust the time-frames, bumping them up to ten minutes work, five minutes rest.  Eight intervals, then, take exactly two hours.

Here’s how it works: Take the eight tasks at the top of your to-do list.  This is important.  Don’t cherry-pick tasks, as it leaves the ones you don’t want to face floating on your list for weeks on end.  As painful as each Tabata may be, it’s also brief enough to be endurable; the same goes for ten minutes of any of your work tasks.  Whip your interval timer out of your gym bag, and set it for eight ten-minute/five-minute repeats.  Fire it up, and jump in on the first task.

When the bell chimes, stop.  Seriously, stop.  It doesn’t matter if you aren’t finished.  Just put down what you’re doing.  You’ll get to it later that day, or; for painful, avoided tasks, in the next day’s Tabata pass.  Then spend five minutes goofing off.  Surf the web, hit the bathroom, fire spitballs at the obnoxious guy two cubicles over.  It doesn’t matter what you do, so long as it’s not work.

But, once the timer next beeps, immediately jump back in for task number two.  Hit it hard, knowing that, as soon as you start, you’re literally just minutes from  moving on.

Rinse and repeat until you’re made it through the two-hour block.

Sure, it doesn’t sound like much.  But the first morning I tried, Tabata My Job helped me blow through more work in two hours than I had in whole days the week prior.  Even better, it allowed me to cross several tasks that had long been looming at the top of my list.  In fact, in future Tabata runs, I discovered that many of the scariest tasks were actually remarkably brief-well withing ten minutes-once I finally buckled down and jumped in.

Preparation Time: 15 minutes
Servings: 8

Filling:

• 8 ounces cream cheese, room temperature
• 1 egg
• 2 teaspoons maple syrup

Cake:

• 6 eggs
• 3 tablespoons butter, melted
• 1/2 cup yogurt
• 1/4 cup maple syrup
• 1 teaspoon almond extract
• 1/2 cup + 1 tablespoon coconut flour, sifted
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 1/4 cup pecans, chopped
• 1 tablespoon maple syrup
• 1 teaspoon cinnamon

1. Preheat oven to 325 degrees F. Grease one 8-inch round cake pan.

2. Beat together all ingredients for cream cheese filling. Set aside.

3. Combine the first five ingredients for cake then add the dry ingredients through the salt. Mix well.

4. Toss pecans, cinnamon and maple syrup together in a separate bowl.

5. Pour cake batter into pan and drop bits of the pecan mixture throughout batter.

6. Top with cream cheese filling and use a knife or tooth pick to swirl it around.

7. Bake for 25 minutes and let cool before slicing.

Preparation

Winter squashes can seem a little daunting because of their size and their hard skins. What is in there anyway? They are totally easy to prepare, though. Ready for this?

How to cook any winter squash: Preheat the oven to 400 degrees F. Cut the squash in half. Scrape out the seeds. Place the squash cut side up in a baking dish with about an inch of water. Bake for 45 minutes to an hour, until a fork easily pierces through the whole squash. Let cool fully before handling, these suckers get HOT.

If you don’t have a sharp knife, there’s another way you can handle this. The microwave. Make sure you stab and poke plenty of holes into the squash before you stick it in the microwave (otherwise it will most certainly explode). Most squashes will be done cooking in about 10 minutes, you want a fork to easily pierce through the flesh. Here’s the disclaimer though – NEVER (ever ever ever) leave the kitchen. If your squash starts squeaking, whistling, or making weird noises that is a sure indicator that too much steam is building up inside and a KABOOM is inevitable. Pause the microwave for a while (maybe even poke more holes in it) and then restart.

Let’s look at five winter squashes that are readily available at most farmers markets and grocery stores. Ready?

Acorn squash

Acorn squash is shaped like (surprise!) an acorn, with distinctive ridges along its sides and a beautiful deep green color. The flesh inside is sweet and orange in color. Acorn squashes are perfect for stuffing with other yummy ingredients, although they’re absolutely awesome just cooked and mashed with grass-fed butter or coconut oil and some cinnamon and nutmeg. I’ve gotten rave reviews for this Stuffed Acorn Squash recipe, but you should try filling them with whatever you like.

Delicata squash

Delicata squash is a cheerful-looking yellow squash with long green stripes and yellow-orange flesh. This squash doesn’t store as well as the other winter squashes because of its’ thin skin, however, the skin itself is edible right along with the squash when you cook it up. Bonus! No need to peel these. Why not try a delicata in this yummy squash salad recipe with kale and pine nuts. Sounds delicious.

Spaghetti squash

Spaghetti squash really is all about the unique texture. This squash is a pale yellow color, about the size of a football or a little smaller, and when finished cooking, the yellow flesh pulls apart into thick, slightly crisp, spaghetti-like strands. Just tease it out with a fork. I like to use half a spaghetti squash as a bowl and mix in olive oil, salt & pepper right into the “bowl” and stir it around. YUM. However, if you’re looking for something a little more well-rounded, make this spaghetti squash with sauce along with some primal meatballs and you will impress even the harshest Paleo skeptics.

Pumpkins

There are dozens of varieties of pumpkins out there, and while everyone’s hacked one apart for a jack-o-lantern, made a pumpkin pie or maybe even Paleo pumpkin pancakes, have you ever tried pumpkin in a savory application? This pumpkin soup with sausage is absolutely awesome. Bonus points if you actually serve the soup inside the pumpkin – it makes its own little tureen!

Butternut squash

Butternut squash, my favorite! These uniquely shaped squashes have a relatively thin skin, making them easy to peel and seed. If you’re lazy (like I sometimes am) you can even cube up the squash and roast it with the skin on. It won’t hurt ya. These squashes are wonderfully sweet and I’ve made everything from a “pasta” sauce (which I serve over meatballs) to green curry. It might go without saying, but they are amazing just roasted with some olive oil, salt & pepper, or coconut oil, cinnamon and nutmeg.

Recipe: Cream of Butternut Squash with Granny Smith Apples & Crispy Pancetta

by Phil McKeon, Executive Chef of 219 An American Bistro

I grabbed some lunch at a great local bistro a few weeks ago with some friends, and ordered this delicious sounding soup. It was *awesome* and could easily be made into a Paleo masterpiece. My friend Phil is the executive chef at that restaurant and was generous enough to share his recipe with us. Make this soup and you will not be disappointed. If you are completely dairy-free you can change out the heavy cream for coconut milk, but it will change the flavor a bit. Try this soup and let us know what you think! It is so comforting on a cold winter’s day.

Ingredients

1/2 cup oil, separated
1 cup diced pancetta or applewood smoked bacon
6 cups diced butternut squash
1 cup diced carrot
1 cup diced yellow onion
bay leaf
1 tsp ground cinnamon
1 tsp ground nutmeg
1 tsp ground ginger
1 tsp ground clove
2 1/2 cups heavy cream
2 cups granny smith apples
4 cups apple juice

Directions

1. In one pot, on medium heat, add 1/4 cup of oil, plus squash, carrot and onion. Cook until soft, stirring occasionally. Add bay leaf, cinnamon, nutmeg, ginger, cloves and cream.
2. Cook until hot and you can poke a toothpick all the way through the butternut squash with ease. Pour the soup into a blender (carefully!) or blend with a stick blender until smooth.
3. Salt & pepper to taste, and add some apple juice to thin it out if it’s not to your liking.
4. In another pot on low heat, add diced apples and apple juice and stir. Cook until apples are soft.
5. In a frying pan, on medium heat, add 1/4 cup of oil and the pancetta or bacon and cook till it’s crispy. Remove from heat and separate the pancetta from the grease.
6. Use a slotted spoon to remove the apples from the pot and add some to a bowl. Pour the butternut bisque over the apples, then garnish it with a little of the crispy pancetta and some freshly chopped parsley.

It’s time for the annual procession of all things carb: potatoes, rolls, cranberry molds, all manner of desserts. Thanksgiving, however, needn’t be a salivating stare down with the spuds. The subject du jour: how you plan to handle the holiday. Primal types seem to fall into two camps when it comes to these occasions. Some say every day is a Primal day, and they go about preparing their Thanksgiving feast the way they do every other meal. If they’re visiting for the holiday, they selectively forage and might even bring a Primal dish of their own (to share or relish alone). Others take a looser approach, balancing the value of family traditions with their Primal interests to forge a reasonable compromise for the day. There’s plenty of room under the Primal tent for both good, old-fashioned moderation and rock solid resoluteness, I’d say. Let’s take a closer look.

The “Taking 20” Approach

Yes, there’s the 80/20 Principle to consider here, and it plays out a little differently for everyone. Some folks stay pretty much fully Primal throughout the year but make their exceptions on special occasions like holidays and other celebrations. The thinking here is, “It’s only one day. I’ll have my stuffing and then go back to normal life the next day. No biggie.” Although I’m not advocating inhaling the Thanksgiving pie all by yourself, I understand the sense of making a moderate concession for the holiday. Every once in a while I’ll take that approach myself. Chalk it up to convenience or nostalgia, but Thanksgiving does only come once a year. Your family may have very meaningful traditions that you enjoy participating in, or you might just reserve a special place in your heart/stomach for a certain annual dish. Some folks will even consider the day a strategic carb-refeeding opportunity. My suggestion is to gauge where you’re at in your Primal journey. Beginners or those interested in weight loss might have a harder time traversing the route of moderation. After all, you don’t want a momentary compromise to derail your progress. However, if you feel you can enjoy it and then return to your Primal track the next day none the worse for the wear, go ahead and partake.

The “Stickin’ to Your Guns” Approach

Of all the days in the year, this can be the most difficult to navigate. Particularly if you’re spending the day with family or cooking with a non-Primal partner, your commitment can get some blowback even if it’s “tolerated” the rest of the year. Rest assured: you’re not a stick in the mud or a killjoy. It’s entirely your right to eat the way you want to on Thanksgiving just like it is every other day. You might choose to explain your reasoning (once again), or you might just try to lay low and avoid the subject for the day. (Comments/anecdotes, anyone?) In the interest of keeping peace and harmony, however, there are plenty of ways to politely turn down the un-Primal fare on the table.

The truth is, there are plenty of ways to make your holiday fully Primal – or any degree between. Whether you’re hosting or visiting, I invite you to look back at our most popular Thanksgiving recipes. They’ll truly an indulgent way to stay on track this holiday, and they’re proof once again that eating Primal doesn’t mean sacrificing taste.

Mark Sisson

If you are an experienced runner then you have likely heard it many times – VO2max limits performance and increasing VO2max causes improvements in performance.

This belief is both widely held and commonly promoted within the running community and has led to runners and coaches devising workouts specifically designed to increase VO2max.  For example, Pfitzinger & Douglas, in their book Road Racing for Serious Runners, devote an entire chapter to training methods for improving VO2max and speed.(1)  In the introduction to the chapter titled Training to Improve VO2max and Speedthey write “Many serious runners know that improving VO2max, or aerobic capacity, is key to racing better.” and “In this chapter, we’ll show you why and how to improve the two main components of racing fitness that runners try to develop with hard workouts – VO2max and basic speed.” In their view VO2max isn’t just important, it is key to racing well.  They spend much of the chapter explaining what VO2max is and prescribing workouts specifically designed to increase it.

Another example comes from Dr Jack Daniels in his book, Daniels Running Formula.  He writes “To optimize VO2max, the runner must stress the oxygen delivery and processing system to its limit while performing the act of running.  I assign a phase of interval training…to accomplish this goal.”(2)  Dr. Daniels thinks VO2max is important enough to assign an entire phase of training to optimizing VO2max.

Runners and coaches aren’t alone in this belief; exercise scientists believe it too.  The link between VO2max and performance is strong enough that physiologists have conducted research studies designed to identify training techniques that will maximize VO2max.(3)

Which, of course, brings us to an obvious question; what does the research have to say on the subject?  After all, any physiological belief this strongly-held and generally taught must be supported by the research, right?

Actually, no, it isn’t supported by the research.

A review of the research (4) on this topic actually reveals that:

·         “…in well trained athletes VO2max remains stable even when performance is shown to increase.”

·         “…in these athletes the correlation between VO2max and aerobic performance can be poor.”

·         “…although rarely acknowledged, in the small longitudinal studies that have linked changes in VO2max with changes in aerobic performance, the data have been unconvincing.”

·         “…studies using chronic obstructive pulmonary disease patients, recreationally active subjects, and endurance-trained athletes did not observe a correlation between the magnitude of training-induced improvements in VO2max and aerobic performance.”

All of these quotes indicate that the link between VO2max and performance is not what many have long believed and promoted.  The fact is that changes in VO2max and performance are not cause/effect as runners have been taught for so many years.  The data does not prove that improving VO2max is what causes improvement in performance; in actuality, the data in support of that belief is slim at best.

In 2009 a group of scientists who knew and acknowledged that the data was equivocal decided to revisit this topic.  They designed a study to settle the issue by having a relatively large cohort of previously untrained subjects undergo a supervised six week cycling program.  By monitoring changes in performance and various physiological parameters, such as VO2max, they were able to provide definitive insights about the link between changes in performance and aerobic capacity.

The basic finding was this – “This study demonstrates that improvements in high-intensity aerobic performance in humans are not related to altered maximal oxygen transport capacity.”

In other words, changes in VO2max did not cause improvements in performance.

Yes, VO2max improved in the subjects.  And, yes, performance improved too.  But the changes are not related to each other.  “The change in VO2max was not related to the change in time trial performance.”

Training does improve both VO2max and performance but these researchers “…demonstrated that these adaptations do not occur in proportion to each other and do not appear to be determined by the same physiological or biochemical parameters.”  In others words, the physiological factors within the body that cause performance to improve are not the same factors that cause VO2max to improve.  The things within the body responsible for VO2max improvements are not the same things within the body that cause performance to improve.

The practical implication of this research is this – training specifically designed to optimize VO2max may or may not be the best training to maximize performance.  Since different factors are responsible for changes in VO2max and performance, then training to optimize VO2max may not fully train those factors responsible for maximizing performance.

Does this mean you should abandon training designed to maximize VO2max?  No, it doesn’t.  It means that coaches and runners should not have a goal to maximize VO2max.  Instead the goal should be to maximize performance.  They should ignore VO2max and focus on performance.  There is no need to ever measure VO2max in an effort to evaluate the effectiveness of a workout or a program.  The only standard by which to judge training effectiveness is performance.

References:

1.  Pfitzinger P, Douglass S, Road Racing for Serious Runners, 1999, Chapter 2

2.  Daniels, Jack, Daniels Running Formula, 1st edition, 1998, page 39

3.  Midgley A, McNaughton L, Wilkinson M., Is there an optimal training intensity for enhancing the maximum oxygen uptake of distance runners? Empirical research findings, current opinions, physiological rationale and practical recommendations.  Sports Med, 35: 117-132, 2006

4.  Vollard N, Constantin-Teodosiu D, Fredriksson K, Rooyackers O, Jansson E, greenhaff P, Timmons J, Sundberg C., Systematic analysis of adaptations in aerobic capacity and submaximal energy metabolism provides a unique insight into determinants of human aerobic performance, J. Appl. Physiol., 106: 1279-1286, 2009

Yesterday I recommended 4000 IU of vitamin D each day as a good starting point for most people. Though, it’s difficult – nay, impossible – to provide a perfect, universal prescription for vitamin D3 intake. People, and their lifestyle behaviors and environmental conditions are just too different. It’s like with diet. Everyone does well with the basic building blocks, stuff like meat, fat,vegetables, fruit, and nuts, but the optimal ratios are going to differ for individuals based on genetics, dietary history, activity level, and glucose tolerance. Everyone needs vitamin D, but multiple confounding factors must be taken into consideration to determine the right dosage. To start with? Yes, 4k is a good starting point. From there, though, things get considerably more complicated – as they always do.

Now, I don’t want to overcomplicate things, however. The same basic advice holds: get unfiltered sunlight, avoid burning, and take supplements when sunlight is unavailable.But I do want you to be aware of certain factors – environmental, climatic, dietary, genetic, etc. – that may affect vitamin D3 production, requirements, and availability.

Skin Color

A person’s skin color affects his or her ability to create D3 in the skin. The darker you are, the longer you must remain exposed for optimal D3 production. Dark skin also protects you from the sun – which is probably why melanin-rich black skin was the default hue for early humans living in equatorial Africa. Among those of us who moved to cooler climates with actual seasons, lighter skin with greater sensitivity to sunlight was selected.

But damn if we aren’t a mobile people, and that mobility throws a monkey wrench into the whole thing. The whitest white guy with Celtic blood running through his veins can live in sun-drenched Southern California, just as a black woman several generations removed from Nigeria might have settled down in Norway. Each is imbued with a vitamin D3 production capability that “conflicts” with their current locale. As far as melanin content and resistance to sunlight is concerned, they’re on permanent vacation. Have they outpaced natural selection? A bit, but they can avoid serious complications by knowing the facts and acting accordingly. Dark skinned folks will need more sun – or supplements to make up for it – while lighter skinned folks need less sun to produce D:

10-45 minutes full sun (without burning) for light skin
2-2.5 hours full sun for dark skin

Diet

No food enters our body in a vacuum. It is a mistake to only think of individual nutrients or vitamins without giving thought to how they might react with the hundreds of other substances you take in on a daily basis. Vitamin D is one of the biggest. What we eat has powerful effects on vitamin D metabolism.

Magnesium – Magnesium is important for bone health because a sufficient amount enables the mobilization of active vitamin D3 – calcitriol. One study even showed that magnesium deficiency resulted in 50% less calcitriol, increased inflammatory markers in the bone, and lowered bone mass.

A Primal diet high/sufficient in magnesium may reduce your need of D3 supplements. If you’re getting plenty of magnesium through leafy greens, nuts, and supplements, you may want to stick to D3 from sunlight or in smaller doses closer to 4,000 IU.

Meat –It has been shown that a Western style plan of omnivory, with particular emphasis onmeat, dairy, and eggs, protects against rickets in the presence of severe vitamin D deficiency. Dunnigan thinks the meat is responsible, and that vitamin D deficiency is necessary but not sufficient for rickets. You’ve also got to avoid the meat to really make the D3 deficiency manifest as something bad.

As Peter said, you can get away with vegetarianism in the tropics, where D3 is plentiful. Moving north requires meat in the diet. It’s probably true that a Primal diet rich in animal protein makes complications from vitamin D3 deficiency uncommon, even without getting much sun or taking many supplements.

Grains – Grains in the diet decrease calcium absorption, thus increasing the demand for vitamin D. Eat grains and you’d better be getting plenty of good sunlight.

Don’t eat grains.

Vitamin A – A heated debate over vitamin A and vitamin D (with a bit of K2 sprinkled in) rages on. The Vitamin D Council boys claim A antagonizes and competes with D, while Chris Masterjohn and the WAPF stress balance of the two for proper function.

Rather than demonize one and exalt the other, just get sun, take supplements when you need them, and eat plenty of beta-carotene in the form of veggies, along with some preformed retinol in the form of liver, eggs, and other animal fats. Don’t take cod liver oil for the DHA/EPA; take half a teaspoon or so for the vitamins. Stick to fish oil for your omega-3s.

PUFA/SFA – People report increased resistance to sunburn since replacing dietary PUFAwith SFA. I’ve definitely noticed similar effects, but I was unable to bring up any literature confirming it. Anyone know more?

Pollution

Remember how they used to warn us about CFCs depleting the ozone layer and letting in too much UV light? That was probably a fairly valid warning, seeing as how full spectrum UV in naturally occurring ratios is what we should be getting. Any kind of imbalance deserves wariness. Strangely enough, now the real issue is insufficient UVB caused by too much ozone. One study found that “urban tropospheric ozone” – a benign-sounding name for manmade air pollution – was to blame for widespread vitamin D deficiency among physically active urban Belgian women who spent plenty of time outdoors in the summer. Rural women doing the same activities at the same time of year were mostly free of deficiency.

In a rare stroke of irony tinged with good news, researchers are even now estimating that the benefits of excess solar radiation due to ozone depletion outweigh the downsides.

Urban sunlight probably isn’t as potent as rural. If you’re primarily an urban dweller who’s unable to get his or her D3 levels to budge despite dedicating time to sunlight, maybe get outside city limits on a regular basis. Go for a hike, have a picnic.

Clouds

Clouds are another confounding factor for vitamin D, but in a very convoluted way. On a completely overcast day with heavy clouds blanketing the sky, 70-90% of the UVB is blocked, which translates to greatly reduced potential for natural D production. Partly cloudy skies, however, have a different effect. The UVB can actually reflect off of the denser clouds and increase in intensity, effectively scattering itself all over the place.

The same thing can happen with UVA, too, but the effect is pretty meager.

Full cloud coverage blocks most of it out. Spotty coverage blocks direct UVB, but may increase effective UVB. As long as you’re aware that UV is still present on semi-cloudy days, you can use your judgment.

Sunscreen

Slather it on, they tell us, and we do it – usually. But does it really protect us? I mean, our proclivity to follow the experts’ advice on sunblock and sun exposure has proven highly effective in the fight against melanoma, right?

Melanoma incidence is way down (it’s not (PDF)).

As sunscreen usage and sales have skyrocketed, skin cancer has plummeted (the opposite has happened).

What’s the deal? Most of the popular sunscreens on the market only offer meaningful protection against UVB rays. I get that. As much as I love a nice dose of vitamin D, too much UVB exposure can lead to sunburns and skin damage. But in letting through most of the UVA while blocking out UVB, they are doing users a massive disservice. The UVA ends up being a huge problem because people are staying out longer without burning. They figure they’re safe, but it’s a false sense of security: isolated UVA exposure (along with decreased D) seems to increase the chance of developing melanoma, the really dangerous kind of skin cancer.

In the end, it seems like getting full spectrum UV is essential for obtaining D3 and protecting yourself. In this case, what works best is what’s most natural – full spectrum sunlight without burning.

(Here’s a cool hack for figuring out how much vitamin D you might be getting based on several factors, like cloud cover, surface altitude, latitude, time of year, etc. It’s imperfect, but a good general guide that’s fun to play with.)

Before phototropic plants began bending toward sunlight, before jellyfish developed ocelli, the light-sensing organs that allow them to distinguish between up (sunlight) and down, before the bikini-clad beach denizens began tanning en masse, and before the first house cat followed the sliver of sunlight around the room all afternoon, our primitive, microscopic marine forebears were flourishing by converting the sun’s energy into chemical energy usable by biological life. You’re probably aware of photosynthesis, the process by which plants, algae, and other organisms do it and produce byproducts like oxygen, but even the unicellular archaea that do not produce oxygen utilize sunlight for energy. And if you aren’t obtaining energy directly from the sun, you’re probably eating the organisms that do. Either way, sunlight directly or indirectly supports all life (well, except for the chemoautotrophs living in deep sea hydrothermal vents feeding off of inorganic energy sources like iron, ammonia, or sulfur).

Humans don’t directly consume sunlight, though. We aren’t breatharians or walking, talking photosynthesizers. Sunlight might feel good and it might brighten up our moods, but we don’t consume it for metabolic sustenance. It does, however, provide the raw material for the 7- dehydrocholesterol in our skin to manufacture the ever-important vitamin D3, or cholecalciferol.

For some organisms, like the naked mole rat with its natural, “preferred” vitamin D deficiency, vitamin D is unimportant. But for most, including man, vitamin D is vital. You might even say it’s the most important vitamin of all. It’s not really even a vitamin, in fact; it’s a secesteroid, a hormonal precursor that closely resembles steroids like cortisol, testosterone, andcholesterol. Most vitamins are exogenous and stem from outside sources. Vitamin D is a different sort of “vitamin.” We mammals make it in-house.

Vitamin D is essential to us. As an equatorial people, we homo sapiens all spent well over half our collective development time bathed in tropical sun, almost year-round. Those of us who flitted off to the South Pacific and other equatorial regions got plenty of the stuff, too. Northerners even developed fair skin with less melanin, which maximized their ability to produce vitamin D from less sunlight. We’ve clearly evolved with the availability of sunlight – and therefore vitamin D3 – as a central stressor to our development.

As you know, the Primal Blueprint is about looking for that perfect storm of evolutionary concordance and modern scientific confirmation. I try to find the eye of the storm and stay there. When it moves, I move with it.

To evaluate whether a food or nutrient or behavior is suitable or not, I:

1. Check out the anthropological records. I look at the historical legacy and ask some questions. Is there evolutionary precedent? Did our ancestors have regular, spotty, or zero access? Clearly, we did, having spent the bulk of our evolution on the equator with regular access to sunlight.
2. Check out the current science and ask more questions. What does the epidemiology show? Are there any randomized controlled trials on the subject? Were they animal studies or human? There is quite a bit of data. Here’s a small taste, and I’ll address more of it tomorrow.

Vitamin D checks out on all levels. We’re not just talking about some exogenous substance which our ancestors may have occasionally come across and which may confer benefits, like bone marrow or polyphenols. This is vitamin D, the active form of which – called calcitriol – is produced in our livers in response to cholecalciferol derived from UV-B radiation. That’s sunlight, a resource readily available to our equatorial ancestors, the importance of which is indicated by the presence of naturally-occurring vitamin D receptors in the body’s cells.

Our bodies clearly consider it essential, but why? What does it do?

• It regulates the levels of calcium and phosphate in the bloodstream, and it promotes the mineralization and growth of bones, working together with calcium, vitamin A, and vitamin K2. Severe deficiency can cause rickets.
• It plays a massive role in the immune response, activating and “arming” the killer T-cells for defense against infections and bacteria.
• It modulates the expression of genes that regulate cell proliferation, apoptosis, and differentiation, suggesting a potential role in cancer incidence. Epidemiology suggestslinks between vitamin D deficiency and most cancers, including breast, colorectal, and pretty much all the big ones.
• It reduces systemic, chronic inflammation.

For something as readily available on any given sunny day, it’s also, surprisingly, in short supply these days. We’re told to avoid the sun at all costs or, if we absolutely must venture out into the light, to apply a layer of sunscreen so thick and physically impregnable that an equal amount of something as inert as lite mayo would be just as effective. Between office jobs without a view, window panes that allow UV-A but not UV-B rays, fleshy embarrassed physiques that never see the light, chubby kids who wear t-shirts to go swimming, and even widespread burqa usage in certain regions, humans just aren’t giving their skin enough opportunities to create vitamin D3. And if it’s an essentiality, it’s probably best to provide your body plenty of opportunities to make (or consume) it.