It rarely makes the headlines but vitamin D deficiency is a big problem in the United States and its impact on public health is significant. Medical experts say that vitamin D helps prevent ovarian, breast and prostate cancer as well as depression and schizophrenia. 40% of the US population is vitamin D deficient, including 32% of doctors.
John Pantel, a clinical dietician at Toledo Hospital, explains that vitamin D gets into our bodies from direct sunlight exposure to the skin. "The sun's exposure to the skin produces vitamin D naturally and so the recommendation is 20-30 minutes of sunlight exposure several times a week," Mr. Pantel said.
The best opportunities to get vitamin D via sun exposure are in the spring, summer and fall. "Generally that is the case because in the winter there is not enough sunlight because the rays do not come in at the right angle," Mr. Pantel said.
It is nearly impossible to get adequate amounts of vitamin D from your diet. Sunlight exposure is the only reliable way to generate vitamin D in your body.