Evolutionary Argument for Optimal Vitamin D Level

Evolutionary Argument for Optimal Vitamin D Level
5 (100%) 3 votes

Should the vitamin D levels found in lifeguards be considered the norm for our species, given the fact that we evolved running around naked all day in equatorial Africa?

Comenta
Comparte

The Institute of Medicine’s target vitamin D level corresponds with what one finds out in the general population. Normal people getting about an hour of sun a day have about 20 to 30 nanograms per milliliter. This is in nanomoles per liter, which corresponds to about 27 nanograms per milliliter, whereas lifeguards, who spend more like eight hours in the sun every day, have abnormally high levels, like over 60. Others, however, interpret this data differently, suggesting that the vitamin D levels in the lifeguards are the ones that are normal, and the “normals” are actually vitamin D-deficient.

We did, after all, live as naked creatures in the East African tropics for about a million years before we began using animal skins as capes to cover our shoulders. But tailored clothing, something like we know it today, was not devised until about 40,000 years ago, when needles first appear in the archaeological record. The invention of tailored clothing may have been an important factor enabling the first modern human beings to settle permanently in Europe, with its cold winters, about 30,000 years ago. In Africa there was plenty of sunshine and plenty of vitamin D. Not so in Europe, where there were long winters, and people covered in clothing.

This must have been when our species first began to evolve a lighter skin as an adaptation to the shortage of sunshine and vitamin D. It wasn’t until we started living in the sunless alleys of smog ridden cities did rickets rear its ugly head, and we had to start fortifying our food supply with D.

So instead of a blood level of 20, maybe we should shoot for what farmers in Puerto Rico get, or lifeguards from Israel and St. Louie.

Just because those levels might really be normal for our species doesn’t necessarily mean, though, that they’re the best. There’s a reason people tan; that’s our body producing more melanin to protect itself. There’s a reason we as a species evolved with a built-in SPF-15 in our beautiful black African skin. So while maybe normal now is too low, maybe normal then was too high.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.

Please consider volunteering to help out on the site.

Images thanks to the US National Library of Medicine and daryl_mitchell / Flickr

The Institute of Medicine’s target vitamin D level corresponds with what one finds out in the general population. Normal people getting about an hour of sun a day have about 20 to 30 nanograms per milliliter. This is in nanomoles per liter, which corresponds to about 27 nanograms per milliliter, whereas lifeguards, who spend more like eight hours in the sun every day, have abnormally high levels, like over 60. Others, however, interpret this data differently, suggesting that the vitamin D levels in the lifeguards are the ones that are normal, and the “normals” are actually vitamin D-deficient.

We did, after all, live as naked creatures in the East African tropics for about a million years before we began using animal skins as capes to cover our shoulders. But tailored clothing, something like we know it today, was not devised until about 40,000 years ago, when needles first appear in the archaeological record. The invention of tailored clothing may have been an important factor enabling the first modern human beings to settle permanently in Europe, with its cold winters, about 30,000 years ago. In Africa there was plenty of sunshine and plenty of vitamin D. Not so in Europe, where there were long winters, and people covered in clothing.

This must have been when our species first began to evolve a lighter skin as an adaptation to the shortage of sunshine and vitamin D. It wasn’t until we started living in the sunless alleys of smog ridden cities did rickets rear its ugly head, and we had to start fortifying our food supply with D.

So instead of a blood level of 20, maybe we should shoot for what farmers in Puerto Rico get, or lifeguards from Israel and St. Louie.

Just because those levels might really be normal for our species doesn’t necessarily mean, though, that they’re the best. There’s a reason people tan; that’s our body producing more melanin to protect itself. There’s a reason we as a species evolved with a built-in SPF-15 in our beautiful black African skin. So while maybe normal now is too low, maybe normal then was too high.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.

Please consider volunteering to help out on the site.

Images thanks to the US National Library of Medicine and daryl_mitchell / Flickr

Nota del Doctor

This is the second in a nine-part series on vitamin D. Be sure to check out yesterday’s video: Vitamin D Recommendations Changed.

For more context, check out my associated blog posts: Vitamin D: Shedding some light on the new recommendations, and Vitamin D from Mushrooms, Sun, or Supplements?.

If you haven’t yet, you can subscribe to my videos for free by clicking here.

Comment Etiquette

On NutritionFacts.org, you'll find a vibrant community of nutrition enthusiasts, health professionals, and many knowledgeable users seeking to discover the healthiest diet to eat for themselves and their families. As always, our goal is to foster conversations that are insightful, engaging, and most of all, helpful – from the nutrition beginners to the experts in our community.

To do this we need your help, so here are some basic guidelines to get you started.

The Short List

To help maintain and foster a welcoming atmosphere in our comments, please refrain from rude comments, name-calling, and responding to posts that break the rules (see our full Community Guidelines for more details). We will remove any posts in violation of our rules when we see it, which will, unfortunately, include any nicer comments that may have been made in response.

Be respectful and help out our staff and volunteer health supporters by actively not replying to comments that are breaking the rules. Instead, please flag or report them by submitting a ticket to our help desk. NutritionFacts.org is made up of an incredible staff and many dedicated volunteers that work hard to ensure that the comments section runs smoothly and we spend a great deal of time reading comments from our community members.

Have a correction or suggestion for video or blog? Please contact us to let us know. Submitting a correction this way will result in a quicker fix than commenting on a thread with a suggestion or correction.

View the Full Community Guidelines

Deja una respuesta

Tu correo electrónico no se publicará Los campos obligatorios están marcados *

Pin It en Pinterest

Share This