Vitamin D status linked to artery health: study

From FoodNavigator.com

Increased levels of vitamin D may improve cardiovascular health and reduce the prevalence of peripheral arterial disease (PAD), suggests a new study.

Moreover, the relationship was consistent across the difference subgroups. “The consistency of the results in these subgroups is noteworthy,” wrote the researchers.

The authors note that the relationship does not prove that increased levels of vitamin D protect against PAD directly, and that higher vitamin D levels may be a marker of general or specific lifestyle practices.

Mechanism

The potential mechanism by which vitamin D may improve cardiovascular health is not known and is “controversial,” wrote the authors.

“In some studies, low 25(OH)D levels have been associated with increased prevalence of coronary heart disease (CHD), stroke, and congestive heart failure. However, low 25(OH)D has been associated with a protective association in other studies,” they stated.

Dr. Melamed added: “We know that in mice, vitamin D regulates one of the hormone systems that affects blood pressure. Since cells in the blood vessels have receptors for vitamin D, it may directly affect the vessels, although this has not been fully worked out.”

The researchers called for large randomised clinical trials to address if vitamin D supplementation could offer protection against PAD.

Vitamin D refers to two biologically inactive precursors - D3, also known as cholecalciferol, and D2, also known as ergocalciferol. The former, produced in the skin on exposure to UVB radiation (290 to 320 nm), is said to be more bioactive. The latter is derived from plants and only enters the body via the diet, from consumption of foods such as oily fish, egg yolk and liver.

Both D3 and D2 precursors are hydroxylated in the liver and kidneys to form 25(OH)D, and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active form that is tightly controlled by the body.

Source: Arteriosclerosis, Thrombosis, and Vascular Biology

Published online ahead of print, April 2008, doi:10.1161/ATVBAHA.108.165886

“Serum 25-Hydroxyvitamin D Levels and the Prevalence of Peripheral Arterial Disease. Results from NHANES 2001 to 2004″Authors: M.L. Melamed, P. Muntner, E.D. Michos, J. Uribarri, C. Weber, J. Sharma, P. RaggiAuthors: M.L. Melamed, P. Muntner, E.D. Michos, J. Uribarri, C. Weber, J. Sharma, P. Raggi

Authors: M.L. Melamed, P. Muntner, E.D. Michos, J. Uribarri, C. Weber, J. Sharma, P. Raggi

Saturday, April 26th, 2008 : Nutritional Supplements : No Comments

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