Oral Supplementation With 25(OH)D_3 Versus Vitamin D_3: Effects on 25(OH)D Levels, Lower Extremity Function, Blood Pressure, and Markers of Innate Immunity

摘要

To test the effect of 25(OH)D_3 (HyD) compared to vitamin D_3 on serum 25-hydroxyvitamin D levels (25(OH)D), lower extremity function, blood pressure, and markers of innate immunity. Twenty healthy postmenopausal women with an average 25(OH)D level of 13.2+-3.9ng/mL (mean+-SD) and a mean age of 61.5 +-7.2 years were randomized to either 20 mug of HyD or 20mg (800IU) of vitamin D_3 per day in a double-blind manner. We measured on 14 visits over 4 months, 25(OH)D serum levels, blood pressure, and seven markers of innate immunity (eotaxin, interleukin [IL]-8, IL-12, interferon gamma-induced protein 10kDa [IP-10], monocyte chemotactic protein-1 [MCP-1], macrophage inflammatory protein beta [MIP-1beta], and "Regulated upon Activation, Normal T-cell Expressed, and Secreted" [RANTES]). At baseline and at 4 months, a test battery for lower extremity function (knee extensor and flexor strength, timed up and go, repeated sit-to-stand) was assessed. All analyses were adjusted for baseline measurement, age, and body mass index. Mean 25(OH)D levels increased to 69.5 ng/mL in the HyD group. This rise was immediate and sustained. Mean 25(OH)D levels increased to 31.0ng/mL with a slow increase in the vitamin D_3 group. Women on HyD compared with vitamin D_3 had a 2.8-fold increased odds of maintained or improved lower extremity function (odds ratio [OR] = 2.79; 95% confidence interval [Cl], 1.18-6.58), and a 5.7-mmHg decrease in systolic blood pressure (p = 0.0002). Both types of vitamin D contributed to a decrease in five out of seven markers of innate immunity, significantly more pronounced with HyD for eotaxin, IL-12, MCP-1, and MIP-1 p. There were no cases of hypercalcemia at any time point. Twenty micrograms (20 mug) of HyD per day resulted in a safe, immediate, and sustained increase in 25(OH)D serum levels in all participants, which may explain its significant benefit on lower extremity function, systolic blood pressure, and innate immune response compared with vitamin D_3.