AUGUSTA, Ga.—Scientists recommend black youths receive 2,000 IU of vitamin D supplementation every day to increase heart health after a study found vitamin D deficiency is associated with arterial stiffness, a risk factor for heart disease and stroke (J Clin Endocrinol Metab. 2010 Jul 21).
Researchers form the Georgia Prevention Institute, Department of Pediatrics, studied 49 male and female black teenagers, aged 14 to 17, who were randomly assigned to either the control group (400 IU/d of vitamin D; n = 24) or the experimental group (2,000 IU/d; n = 25). The American Academy of Pediatrics recommends this age group receive 400 IU of vitamin D per day.
However, the study found subjects taking 400 IU of vitamin D per day did not achieve vitamin D sufficiency, while their peers who took 2,000 IU of vitamin D on average became vitamin D sufficient. The experimental group reached significantly higher 25-hydroxyvitamin D [25(OH)D] serum concentrations at eight and 16 weeks compared to the placebo group.
Researchers measured arterial stiffness in study subjects using pulse wave velocity (PWV), a non-invasive procedure where a pulse is emitted at two arterial sites. PWV increased from baseline (5.38 +/- 0.53 m/sec) to posttest (5.71 +/- 0.75 m/sec) in the control group (P = 0.016), whereas in the experimental group, PWV decreased from baseline (5.41 +/- 0.73 m/sec) to posttest (5.33 +/- 0.79 m/sec) (P = 0.031). This shows vitamin D supplementation at significant doses may protect vascular systems.
Additionally, total body fat mass at baseline was significantly and inversely associated with 25(OH)D concentrations in response to the 2,000-IU supplement across time.
