The effect of vitamin D supplementation on arterial stiffness in an elderly community–based population

• Sixty–one percent of older patients screened had serum 25OHD levels <50 nmol.
• Significant decreases in Augmentation Index in 100,000IU cholecalciferol group were noted.
• Use of IM cholecalciferol for the treatment of vitamin D deficiency may not be efficacious.
• Further trials exploring arterial stiffness and its links with vitamin D deficiency are needed.

Vitamin D deficiency may lead to impaired vascular function and abnormalities in central arterial stiffness. We compared the effects of two different doses of vitamin D3 on arterial stiffness in an elderly population with deficient serum 25–hydroxy–vitamin D levels. A total of 119 known vitamin D deficient (<50 nmol/L) subjects were randomized to receive either 50,000 international units (IU) or 100,000 IU single intramuscular vitamin D3. In the group that received 100,000 IU vitamin D, median pulse wave velocity decreased from 12.2 m/s (range, 5.1–40.3 m/s) to 11.59 m/s (range, 4.3–14.9 m/s) after 8 weeks (P = .22). A mean decrease of 3.803 ± 1.7 (P = .032) in augmentation index (a measure of systemic stiffness) was noted. Only 3/51 (5.8%) who received 100,000 IU vitamin D reached levels of sufficiency (>75 nmol/L). A significant decrease in augmentation index was seen in the group that received 100,000 IU vitamin D. Serum levels of 25–hydroxy–vitamin D were still deficient at 8 weeks in the majority of patients, which may be attributable to impaired bioavailability.