The importance of maintaining healthy levels of vitamin D has been demonstrated again and again by the results of scientific studies. Low levels of vitamin D have been linked to a growing number of health problems including heart disease, cancer, stroke, chronic pain, and even all-cause mortality. Vitamin D is particularly important in its role as a regulator of calcium levels and in the maintenance of healthy bones. Low vitamin D levels have, in the past, been linked to increased fracture risk. A recent study adds to the body of evidence in this area, showing that low blood levels of vitamin D are associated with an increased incidence of hip fractures in post menopausal women.
The study examined 400 patients that had experienced hip fractures and 400 that had not. All of the women were postmenopausal, aged 50-79, not using hormone therapy and were part of the larger WHI-OS (Women’s Health Initiative Observational Study). The blood levels of 25-hydroxyvitamin D (25[OH]D – a non-active storage form of vitamin D) of each woman were analyzed and compared to the incidence of hip fracture over the next seven years. The results demonstrated that hip fracture risk was up to 70% greater for women with 25[OH]D levels less than 47.6nmol/L than for those with higher levels (greater than 70nmol/L). The optimal level of 25[OH]D for the maintenance of bone health has not been officially established, but studies suggest that levels of at least 78nmol/L are desirable, with a range of 92-105nmol/L being ideal.
The mechanism by which higher vitamin D levels protect against fracture risk is unknown. However, levels of C-terminal telopeptide, a marker of bone resorption, tended to be higher in women with the lowest 25[OH]D levels. This suggests that lower levels of vitamin D may lead to an increased rate of bone resorption. Another possibility is that low vitamin D levels are related to reduced muscle strength and an increased chance of falling.
ACauley JA, LaCroix AZ, Wu L, Horwitz M, Danielson ME, Bauer DC, Lee JS, Jackson RD, Robbins JA, Wu C, Stanczyk FZ, LeBoff MS, Wactawski-Wende J, Sarto G, Ockene J, Cummings SR. Serum 25-Hydroxyvitamin D Concentrations and Risk for Hip Fractures. Annals of Internal Medecine, 2008; 149(4): 242-250.
For more information see D3-5000 or Vitamin D3
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