Effect of a high dose of vitamin D on a rabbit model of atherosclerosis.

Multifactorial factors have been involved in atherosclerosis. An association has been shown between osteoporosis and carotid atherosclerosis. This work evaluates the effect of vitamin D on regression of atherosclerosis. Forty-eight male rabbits were divided into: Group Ia: [Standard diet + saline for 4 weeks]; Group I b: [Standard diet + a high dose of vitamin D3 daily for 4 weeks]; Group IIa: [Cholesterol–enriched diet for 4 weeks]; Group IIb: [Cholesterol–enriched diet + a single high dose of vit D3, daily for 4 weeks. At the end of 4 weeks, the rabbits were sacrificed for assay in serum lipid profile, C reactive protein (CRP), vitamin D3 metabolite, calcium, soluble adhesion molecules (sVCAM and sICAM) and nitrite (NO) and malondialdehyde (MDA) released from isolated aortic rings. Results showed that vitamin D produced a significant reduction in the sera of lipid profile, CRP, and adhesion molecules, associated with a non-significant change in serum calcium and a significant increase in the body level of vitamin D3. Addition of vitamin D to the incubated aortic rings of the atherosclerotic rabbits resulted in a significant increase in NO and decrease in MDA release. It could be concluded that vitamin D has anti-atherosclerotic effects, and may exert these effects by inhibiting lipid peroxidation and stimulation of nitric oxide, resulting in attenuation of the inflammatory atherosclerotic process.