Boning up on vitamin D: Can UVB from sunlight and tanning beds reverse osteoporosis?

Note: The comments on this blog are for information only. Do not make any changes in sunlight exposure, tanning-bed exposure or nutritional habits without first consulting a medical professional.

In our aging society, fractures due to osteoporosis are pandemic. Most elderly people suffer from the disease, which results when the bones lose their calcium, becoming porous and weak. Because the disease manifests itself so frequently in the elderly, osteoporosis in considered to be an inevitable consequence of aging. Nothing could be further from the truth. Osteoporosis is not only evitable, but it is also reversible.

Can sunlight exposure reverse osteoporosis? The answer is an unequivocal “yes!” I had long known that osteoporosis was at least partly reversible in patients who were given a program of weight-bearing exercise. But it was surprising to learn that even without exercise, an impressive increase in bone density could be achieved. In a profoundly important piece of research, the effects of sunlight on bone were determined. The subjects were elderly women—stroke victims—who had low blood levels of vitamin D. In a 12-month study, 129 of these women were exposed to regular sunlight and another 129 remained indoors. The results were startling: the sunlight group increased bone mass by an average 3.1%; in the non-sunlight-exposed group, bone mass decreased by 3.3% (Sato, Y. et al. Neurology 2003;61:338-42). That is a difference in bone mass of 6.4% between the two groups. Is this important? The risk of fracture increases two to three times for every 10 percent drop in bone density! (Nguyen, T. et al. BMJ 1993;307:1111-15). Vitamin D levels in the sunlight group also increased by 400%. The most impressive result? The sunlight group had only one fracture. The indoor group had six.

Another study, this time using elderly Alzheimer’s victims as subjects, showed similar benefits of sunlight. (Sato, Y. et al. J Bone Miner Res. 2005;20:1327-33.) The experiment was similar to the one just mentioned, in that one group was sunlight exposed for one year, and the other was kept in a hospital. In the sunlight group there was a 220% increase in vitamin D levels in one year, and bone mass increased by 2.7%. In the sunlight-deprived group, bone mass decreased by 5.6%. In the sunlight group, there were three fractures; in the sunlight deprived group there were eleven. In other words, the sunlight deprived group was 3.7 times more likely to have a fracture. Can you imagine what might be accomplished over several years of sunlight exposure coupled with exercise?

Could tanning-bed exposure work as well as sunlight exposure in reducing osteoporosis and its subsequent fractures? Research has shown that Those who use tanning beds have levels of vitamin D that are 90% higher than those who do not use tanning beds; tanning-bed users also have significantly higher bone density. (Tangpricha, V. et al. Am J Clin Nutr 2004;80:1645-49.) Tanning beds, of course, produce vast quantities of vitamin D in a short time.

It appears that safe, sane and regular exposure to UVB dramatically reduces fractures and enhances the quality of life.