Vitamin D in a New Light

... Sensible sun exposure should be encouraged, not maligned. If one avoids sunburn, the sun’s health-giving benefits far outweigh its detrimental effects. A large body of evidence indicates that sunlight does not cause the most lethal form of skin cancer, malignant melanoma. A U.S. Navy study found that melanoma occurred more frequently in sailors who worked indoors all the time. Those who worked outdoors had the lowest incidence of melanoma. Also, most melanomas appear on parts of the body that are seldom exposed to sunlight (Arch Environ Health 1990;45:261–267). Sun exposure is associated with increased survival from melanoma (J Natl Cancer Inst 2005;97:195–199). Another study showed that people who had longer lifetime exposure to the sun without burning were less likely to get melanomas than those with less exposure (J Invest Dermatol 2003;120:1087–1093.)

The rise in skin cancers over the last 25 years parallels the rise in use of sunscreen lotions, which block vitamin D-producing UVB radiation but not cancer-causing ultraviolet A radiation (UVA). (Newer sunscreen lotions also block out UVA.) Each year there are 8,000 deaths from melanoma and 1,500 deaths from nonmelanoma (squamous and basal cell) skin cancer. Surgical excision of nonmelanoma skin cancers cures them, except in rare cases where the growth has been allowed to linger for a long time and metastasize. Dr. John Cannell, Executive Director of the Vitamin D Council, makes this point: 1,500 deaths occur each year from non-melanoma skin cancer, but 1,500 deaths occur each day from other cancers that vitamin D in optimal doses might well prevent. (The Vitamin D Council website is an excellent source of information on vitamin D.) ...