Vitamin D Photosynthesis and Elderly Skin
As the skin ages, there is a decline in the cutaneous levels of 7-dehydrocholesterol, resulting in a marked reduction of the skin's capacity to produce vitamin D3. [1] However, Vanderschueren et al. concluded that renal capacity to synthesize 1,25(OH)2D, in addition to 25(OH)D production in the skin in response to sunlight, may be relatively well conserved, even in elderly community-dwelling men. [2]
Despite the up to fourfold reduction in vitamin D3 production in a 70-year-old compared to a 20-year-old, the skin has such a high capacity to make vitamin D3. Elders exposed to sunlight will produce an adequate amount of vitamin D3 to satisfy their vitamin D requirement. [3, 4]
References
1. MacLaughlin J, Holick MF. Aging decreases the capacity of human skin to produce vitamin D3. J Clin Invest. Oct 1985;76(4):1536-8.
2. Vanderschueren D, Pye SR, O'Neill TW, et al. Active vitamin D (1,25-dihydroxyvitamin D) and bone health in middle-aged and elderly men: the European Male Aging Study (EMAS). J Clin Endocrinol Metab. Mar 2013;98(3):995-1005.
3. Chuck A, Todd J, Diffey B. Subliminal ultraviolet-B irradiation for the prevention of vitamin D deficiency in the elderly: a feasibility study. Photodermatol Photoimmunol Photomed. Aug 2001;17(4):168-71.
4. Chel VG, Ooms ME, Popp-Snijders C, et al. Ultraviolet irradiation corrects vitamin D deficiency and suppresses secondary hyperparathyroidism in the elderly. J Bone Miner Res. Aug 1998;13(8):1238-42.
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