Vitamin D(3) Supplementation for 16 Weeks Improves Flow-Mediated Dilation in Overweight African-American Adults.
Am J Hypertens. 2011 Feb 10.
Harris RA, Pedersen-White J, Guo DH, Stallmann-Jorgensen IS, Keeton D, Huang Y, Shah Y, Zhu H, Dong Y.
Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta, Georgia, USA.

Background A growing body of evidence has linked vitamin D deficiency to increased risk of cardiovascular disease. Vitamin D deficiency is also more common in African Americans for whom an increased cardiovascular disease risk exists. This study sought to test the hypothesis that 16 weeks of 60,000 IU monthly supplementation of oral vitamin D(3) would improve flow-mediated dilation (FMD) in African Americans, whereas no change would be observed in the placebo group.

Methods A randomized, double-blind, placebo-controlled clinical trial was conducted. Fifty-seven African-American adults were randomly assigned to either the placebo group or vitamin D group.

Results Following 16 weeks of placebo (n = 23; mean age 31 ± 2 years) or 60,000 IU monthly oral vitamin D(3) (n = 22; mean age 29 ± 2 years), serum concentrations of 25-hydroxyvitamin D OH)D) increased from 38.2 ± 3.0 to 48.7 ± 3.2 nmol/l and 34.3 ± 2.2 to 100.9 ± 6.6 nmol/l, respectively. No changes in serum parathyroid hormone (PTH), serum calcium, or urine calcium/creatinine were observed following either treatment. Following 16 weeks of treatment, significant improvements in FMD were only observed in the vitamin D group (1.8 ± 1.3%), whereas the placebo group had no change (-1.3 ± 0.6%). Similarly, the vitamin D group exhibited an increase in absolute change in diameter (0.005 ± 0.004 cm) and FMD/shear (0.08 ± 0.04 %/s(-1), area under the curve (AUC) × 10(3 following treatment, whereas no change (-0.005 ± 0.002 cm and -0.02 ± 0.02 %/s(-1), AUC, respectively) was observed following placebo.

Conclusion Supplementation of 60,000 IU monthly oral vitamin D(3) (~2,000 IU/day) for 16 weeks is effective at improving vascular endothelial function in African-American adults
.American Journal of Hypertension (2011). doi:10.1038/ajh.2011.12. PMID: 21311504
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Summary: Adding 2000 IU vitamin D for 16 weeks

• Increased blood level from 14 ng to 40 ng
• Blood vessel increased in diameter
• Flow-mediated dilation improved by 1.8
  • (wonder how good 1.8 is)

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See also Vitamin D Life

• Overview Dark Skin and Vitamin D
• All items in Dark Skin and Vitamin D 174 items as of Nov 2011
• Vitamin D race and cardiovascular - Jan 2010 file
• Blacks may not need as much Vitamin D many articles
• Overview: Strokes and vitamin D
• Metabolic Syndrome adults 4X more likely to have less than 20 ng of vitamin D – Jan 2011
• Hypertension more likely with less vitamin D - Dec 2010
• Perhaps just 40 ng of vitamin D if high latitude or dark skin
• Need to avoid the sun during the summer in Duhai - any links to low vitamin D in Middle East
• The darker the skin the less the vitamin D – July 2010
• Lack of vitamin D closely associated with black health disparities – Nov 2010 - Great charts
• Perhaps just 40 ng of vitamin D if high latitude or dark skin
• Vitamin D Council vs FDA concerning vitamin D deficiency in blacks and others - June 2011
• Do blacks have a 5 year life penalty due to low vitamin D
• Improved blood flow in blacks with just 2000 IU of vitamin D – Feb 2011
• Hypothesis that lack of vitamin D increases blood pressure in blacks – July 2010
• Telomeres improved when obese blacks took 2000 iu of vitamin D daily – Oct 2011