Daily supplements of 20 micrograms per day HyD were associated with a 5.7 mmHg decrease in systolic blood pressure, compared with an equal dose of vitamin D (800 IU), according to results published in the Journal of Bone and Mineral Research.
In addition, while both types of vitamin D contributed to a decrease in 5 out of 7 markers of innate immunity, the benefits were “significantly more pronounced” for HyD for four of the markers, add the researchers.
“The higher and faster increase in circulating level of 25(OH)D reached with HyD compared with vitamin D3 may explain the benefit of HyD on systolic blood pressure reduction, improvement in lower extremity function, and the more pronounced reduction in several markers of innate immunity among health postmenopausal women,” wrote the researchers, led by Heike Bischoff-Ferrari, MD, DrPH, director of the Centre on Aging and Mobility at the University of Zurich.
Vitamin D forms
Vitamin D refers to two biologically inactive precursors - D3, also known as cholecalciferol, and D2, also known as ergocalciferol. Both D3 and D2 precursors are transformed in the liver and kidneys into 25- hydroxyvitamin D (25(OH)D), the non-active 'storage' form, and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active form that is tightly controlled by the body.
Many researchers agree that many people are vitamin D deficient and need vitamin D supplements, but the form and recommended dose are still hotly debated.
Several studies have reported that the D3 form of the vitamin is more potent that D2, with a study led by Robert Heaney, MD, from Creighton University in Nebraska reporting earlier this year that D3 was 87% more potent than D2 (Journal of Clinical Endocrinology & Metabolism, doi: 10.1210/jc.2010-2230).
“As an alternative strategy to enhance 25(OH)D levels, supplementation with the 25(OH)D3 metabolite itself (HyD) has been suggested,” explained Dr Bischoff-Ferrari. “Compared to vitamin D3, HyD has hydrophilic properties, has a much shorter half-life of 8 to 11 hours after oral administration, and causes a rapid increase in serum 25(OH)D levels.”
Study details
The researchers recruit 20 healthy postmenopausal women with a mean age of 61.5 and an average 25(OH)D level of 13.2 ng/ml. The women were randomly assigned to receive either 20 micrograms of HyD or 20 micrograms (800 IU) of vitamin D3 per day for 4-months.
The 25(OH)D3 and vitamin D3 ingredients used in the study was provided by DSM Nutritional Products as spray dried powders stabilized with DL-alpha tocopherol.
Results showed that the HyD group displayed an “immediate and sustained” increase in 25(OH)D levels to 69.5 ng/ml, compared to a “slow increase” to 31 ng/ml in the vitamin D3 group.
In addition, “women on HyD compared with vitamin D3 had a 2.8 fold increased odds of maintained or improved lower extremity function”, report the researcher, “and a 5.7 mmHg decrease in systolic blood pressure”.
“Our results show that oral supplementation with HyD (25(OH)D3 metabolite) at a dose of 20 micrograms per day resulted in a safe, immediate and sustained increase in 25(OH)D levels in all participants,” wrote
“The higher and faster increase in circulating level of 25(OH)D reached with HyD compared with vitamin D3 may explain the benefit of HyD on systolic blood pressure reduction, improvement in lower extremity function, and the more pronounced reduction in several markers of innate immunity among health postmenopausal women.”
Source: Journal of Bone and Mineral Research
Published online ahead of print, doi: 10.1002/jbmr.551
Authors: H.A. Bischoff-Ferrari, B. Dawson-Hughes, E. Stöcklin, E. Sidelnikov, W.C. Willett, E.J. Orav, H.B. Stahelin, S. Wolfram, A. Jetter, J. Schwager, J. Henschkowski, A. von Eckardstein, A. Egli