Homo sapiens evolved in Africa as a hairless ape. That creature spent LOTS of time outside, with a prodigious amount of skin exposure in a nice sunny environment. Today homo sapiens is largely an indoor mammal, and typically covers up a good deal of skin when venturing outside. Even when in a relaxed stance, say on a beach vacation, gobs of sunscreen is applied. This all adds up to much less Vitamin D synthesis happening in the skin cells. Hairless ape was designed to receive a lot of Vitamin D. In fact, people who are extremely deficient in Vitamin D (less than 12 ng/mL) will respond rapidly to sun exposure, and serum levels will rise quickly. People who are marginally deficient (between 30 and 50 ng/mL) achieve optimal levels (50-80 ng/mL) more slowly. This can be taken as evidence that mankind really needs a minimal level to be fit. One exception to this rapid repletion is in the obese. It is very difficult to get obese people “up to speed” with Vitamin D, because, as a fat-soluble vitamin, it “hides” in the fatty tissues and is not released into the circulation unless very high levels (20,000 or more IUs daily) are pushed for a while. The most elegant solution is to have the obese person lose weight — then the Vitamin D stored in their fat cells is automatically delivered into the circulation and thus to all the tissues.

Besides not hanging out naked in the tropical sun, humans today are almost universally Vitamin D deficient because we have not yet found a reliable way to force supplementation. Most naturally occurring sources of Vitamin D are in foods that many people don’t eat at all. For example fish livers, and organ meats from other critters (kidney, heart, etc). Not generally on the menu. Plus, our culture is pretty fat phobic (that’s getting a little better with the more appropriate switch to carb phobia… I’d much rather people focus on good fats and vegetables and forget about refined carbs in the diet). Luckily, most doctors are now tuned into Vitamin D and checking for, and supplementing, deficiencies in their patients. Vitamin D3 (the preferred, bio-identical form) is inexpensive. Don’t be bamboozled into taking the drug form — E2, also known as ergocalciferol — which is way more expensive and doesn’t work nearly as well. Cholecalciferol, or Vitamin D3, is the form you want. A year’s supply should be well under $50.

Probably the most important early warning that we had become woefully deficient in this broadly useful, fat-based vitamin, was an article by Reinhold Vieth (U Toronto) published in 1991 “Vitamin D Supplementation, 25-hydroyvitamin D concentrations, and safety,” (Am J Clin Nutr 1999 May;69(842-56)). This article was recently cited by John Cannell, MD, widely known as the current top Vitamin D expert (see his comprehensive website: www.VitaminDCouncil.org) as his “aha” moment for his dedication to Vitamin D research. All statements in this small article has published references that can be found on Dr. Cannell’s site.

Most of us know that Vitamin D is very important for bone density. It is equally, if not more, important that calcium. The issue of bone density will be addressed in another column. Half a century ago, scientists were under the mistaken impression that Vitamin D could be “toxic” at relatively modest doses. That’s because a fairly small dose (400 IUs) was considered effective in preventing rickets (a soft-bone Vitamin D deficiency disease) in England. Somehow, half of that infant dose was deemed an appropriate adult supplementation level as an additive, apparently supposing the rest of the D was being obtained from sunlight and organ meats (decidedly more popular on the East side of the Atlantic than in the US). There was, however, no research to back up these assumptions. Further, if the objective for Vitamin D supplementation was simply to prevent rickets, there wouldn’t be a big fuss. Vitamin D has many more crucial roles in mammals and supplementation has become a necessity for almost everyone.

Increasing evidence, which means published research, exists for Vitamin D3 in helping slow the progress of various auto-immune diseases. The largest amount of research is in the study of Multiple Sclerosis. There is no doubt that MS incidence correlates with more northern latitudes. Relative lack of Vitamin D is likely the culprit. There is growing evidence that Lupus outcomes are improved with adequate serum Vitamin D levels.

Vitamin D has been shown to improve asthma, especially those patients who don’t do well with inhalers. Steroidal inhalers seem to help the subset of asthma patients who have evidence of allergic responses to airborne irritants in their lungs and bloodstream. This is called “reactive airway disease” or airway eosinophilia (from high “eosinophils” which are a type of white blood cell which signals allergen exposure). If you experience wheezy breathing or shortness of breath which doesn’t respond to rest, make sure to check out your Vitamin D3 levels with a blood test, and bring them into the 50-80 ng/mL range.

Vitamin D also improves arthritis, and nagging body aches in general. Vitamin D is a crucial supplement for fibrymyalgia patients. Make sure to always take your Vit D supplement with some fat. For example, with a spoonful of full-fat yogurt, or with a mouthful of a dish containing egg or meat or olive oil. Make sure your Vitamin D supplement is oily. Dry D doesn’t work as well.

Vitamin D improves mood. Whether there is truly a serotonin-enhancing, anti-depressive effect or whether it’s because you just feel better physically with optimal Vit D levels onboard, is not yet clear. Either way though, it’s a good deal. Possibly the most interesting new tidbit about Vitamin D recently in the news is about telomere lengthening.

Telomeres are the protective caps on the ends of our chromosomes, which are the tightly coiled “X” shaped bits of DNA stored in the nucleus of every single one of our cells. This genetic material is the blueprint for our personal destiny. Every time a cell replicates, and the DNA divides, a little bit of the tip is lost, leading inexorably to ageing. Slowing down ageing by helping extend the life of the telomeres is very real, and cutting edge science. If you don’t know your Vitamin D3 levels, put that on your “to do” list before another winter rolls by.