Known as the "sunshine vitamin, because it is made in the skin when exposed to ultraviolet light from the sun, Vitamin D has long been known as a vital vitamin for healthy bones. When in severe short supply, children develop rickets and adults develop osteomalacia; in both these conditions the bones become soft because of insufficient calcium. Now, however, we have come to learn that vitamin D is vital for many more functions than simply the absorption of calcium from the intestine: indeed every cell in the body has "receptors" for vitamin D. In practice this means that vitamin D has a role in a variety of cellular functions and shortage seems to be associated with an astonishing array of different problems.
Problems from Vitamin D Shortage
Bone Problems: severe deficiency causes rickets and osteomalacia - softening of the bones caused by calcium deficiency. Also bone pains and tenderness and low back pain.
Neuro-Muscular problems: the elderly are more likely to have falls if short of vitamin D; muscle pains and weakness are symptoms, but depression, dementia, Multiple Sclerosis and Schizophrenia may all be more common.
Excess inflammation in the body - various aches and pains and even psoriasis.
Asthma and Eczema more common in Vitamin D deficient.
Cancer and Diabetes.
Worse pregnancy outcomes.
Who is at Risk of Vitamin D deficiency?
Since the natural source of Vitamin D is sunshine, anyone who lives in Northern Latitudes (including the UK!) is at risk - especially if they don't spend enough time outside. Generally we make Vitamin D in the summer months and live off our reserves during the winter; hence our lowest levels are in late spring. Especially at risk are the overweight, the dark skinned, the elderly (who aren't so efficient at making vitamin D in the skin) and the over-clothed. Note that high SPF (sun protection factor) sunscreens block out 95% of the vital sunshine needed to make vitamin D. Note also that certain medications interfere with the management of Vitamin D by the body.
How do you get your Vitamin D?
Sunshine is the most natural way; if a normal person has a reasonable sunbathe (don't get burned and risk skin cancer!) your body makes over 20,000 i.u.s (international units) of Vitamin D. Compare that to the normal dose of Vitamin D you get on prescription of 800 i.u.s per tablet! The "right" dose is somewhat controversial; a blood level below 30 (nanograms per ml) will probably warrant treatment but up to 200 is safe and 40 - 60 is optimal! I therefore take one 5,000 unit pill of cholecalciferol (this is stronger than ergocalciferol - the other readily available source of Vitamin D); this can easily be bought on the web.
Since the benefits are potentially so great and the side-effects so trivial to most people, for me this is one of the truly great, rationale supplements available today!
Doctor Bernard Shevlin