Environmental & Genetic Influences on Vitamin D Status

Environmental & Genetic Influences on Vitamin D Status

The purpose of this study is to determine the effect of environmental and genetic influences on Vitamin D status.

Vitamin D deficiency is a common problem. The principal source of vitamin D for humans is solar exposure, with cutaneous synthesis of vitamin D by photoconversion of 7-dehydrocholesterol in the skin to pre-vitamin D3. Latitude, altitude, season, skin pigmentation, and age are recognized factors that influence how much vitamin D can be made by solar exposure. Surprisingly, Vitamin D deficiency has been described in people dwelling in southern Florida and in surfers in Hawaii. We hypothesize that genetic variations in vitamin metabolism accounts for these differences.

Inclusion Criteria:

• Able to consent and come for a study visit.
• Male or female between ages 18-60.
• Sun exposure >3 hours daily for at least 5 days weekly for the last 3 months.

Exclusion Criteria:

• Unable to consent or come to a visit
• Taking Vitamin D supplements, anticonvulsants, barbiturates, steroids, having granulomatous disease, or liver or kidney disease as these medications and conditions interfere with Vitamin D metabolism.
• Related to another participant by blood.