Even If You Live in Sub Tropical Environments You Can Be Vitamin D Deficient

Vitamin D deficiency has been observed among many populations in the northern United States. But few studies have examined the prevalence of vitamin D deficiency in areas of high sun exposure, such as Arizona.

A new study has shown adults in southern Arizona are commonly deficient in vitamin D, particularly those with darker skin who produce less vitamin D in response to sunlight.

More than a quarter of Arizona adults tested had dangerously low blood levels of the vitamin.

Sources:

• American Journal of Clinical Nutrition, 87(3): 608-613 March 2008

Why Vitamin D Supplements Are NOT the Same as Sunlight

The assumption that vitamin D supplements will protect you against diseases associated with low vitamin D levels is incorrect, according to Australian researchers. The report found that vitamin D supplements are immunosuppressive and may actually make diseases worse.

Vitamin D Nuclear Receptor (VDR) influences the expression of over 1,000 genes, including those associated with diseases such as cancer and multiple sclerosis. According to the new study, supplemental vitamin D actually blocks VDR activation, which is the opposite effect to that of sunshine.

Instead of positively impacting gene expression, vitamin D supplements appear to suppress your immune system.

Vitamin D deficiency, the researchers pointed out, is likely not a cause of disease but rather is a result of the disease process. And increasing vitamin D intake may make the diseases worse.

The body regulates production of all the vitamin D it needs, the researchers said, and dysregulation of vitamin D by supplementation has been associated with many chronic diseases.

Sources:

• Science Daily January 27, 2008

• BioEssays January 2008, Volume 30, Issue 2, Pages 173-182