Vitamin D: The Big Picture

I won't say that this will be my absolutely last post on vitamin D, but I think that a quick summary of what I've written previously and how this fits into the big picture on health is in order. I'm not going to give references here; there are lots of links in my previous posts where this information can be verified and leads followed up.

It's estimated that over one billion people worldwide are vitamin D deficient, and while that number is huge, it should appear even greater to the typical reader of this blog, because whites in Europe and North America and even sunny Australia are the overwhelming majority of those affected.

Humans evolved in the sun, and even until quite recently, historically speaking, most everyone farmed, hunted, and fished outdoors. The difference in skin color between Africans and Europeans is not merely for show; it reflects the fact that an important physiological function is involved. We now work indoors, avoid the sun, and live in northern latitudes, so we are lacking in a crucial nutrient that is vital for our health.

Deficiency of vitamin D can and does lead to major health problems and early death, or increased morbidity and mortality as the epidemiologists like to say. A sufficient blood level of this vitamin causes, statistically speaking, major reductions in the incidence of cancer (including but not limited to colon, breast, prostate, and lung cancer), heart disease, depression, osteoporosis, hypertension, autoimmune diseases including multiple sclerosis, low birth weight, chronic pain, and chronic fatigue. These are the diseases of Western civilzation; the ramifications for public health are enormous.

The discoveries concerning vitamin D over the past five years or so are revolutionary, and in my opinion rank as high as the discovery that smoking is harmful to health. The numbers of people affected are of the same magnitude in each case, and both D deficiency and smoking have major deleterious consequences. In fact, of the two, vitamin D deficiency may well be worse. For example, D deficiency appears to damage pulmonary function even more than cigarettes. In any case, vitamin D deficiency affects all age groups.

At latitudes above about 38 degrees north, it's difficult for much of the year to obtain adequate exposure to the sun for vitamin D production, and supplements must be taken to ensure an sufficient blood level. This is what the debate among public health authorities is all about. While vitamin D can be toxic in high doses, concerns about toxicity appear to be way overdone, and yet those in charge of such things continue to cling to the old ways. (Virtually all cases of D toxicity in the literature are either industrial accidents, such as the massive overfortification of milk, overdoses upon the failure to follow directions on supplement bottles, or in one case the use of vitamin D concentrate as cooking oil.)

The epidemic of cancer, heart disease, depression, dementia, and bone fractures in the elderly could be greatly diminished if everyone had adequate levels of vitamin D. The advice to avoid the sun is both outdated and dangerous. Even so, in many places and seasons adequate solar exposure is difficult to obtain. A massive program of supplementation is needed, probably through greater fortification of food.

Until then, one should ensure that one's vitamin D intake is adequate. If you or anyone close to you suffers from any of the illnesses mentioned above, you ought to have a vitamin D level test done and then, if it's low, ensure that supplementation or proper solar exposure is undertaken. Your life could depend on it.