People often assume that residents of sunny climates easily absorb sufficient vitamin D, but a surprisingly large number suffer from vitamin D deficiency, according to WebMD. For example, 40 percent of elderly Florida residents suffer from a lack of vitamin D.
Absorption of sufficient vitamin D helps prevent rickets, osteoporosis and bone pain, writes WebMD. Vitamin D is also important for the treatment of high blood pressure and high cholesterol and may play a role in treating diabetes, multiple sclerosis and rheumatoid arthritis. Vitamin D may also improve some skin conditions, such as vitiligo, psoriasis and lupus vulgaris. In addition, it may boost the immune system and help prevent autoimmune disease.
Vitamin D is also important because it regulates calcium and phosphorus in the body, says WebMD. Sunlight provides the most abundant source of vitamin D. Six days of casual sun exposure can erase the effects of 49 days without sunlight. Older people often have more difficulty absorbing vitamin D from sunlight. For this reason the elderly are more likely to benefit from vitamin D supplements.
Vitamin D occurs naturally in only a few foods, as stated by WebMD. Herring, mackerel, sardines and tuna contain small amounts of vitamin D.