Effects of Vitamin D3 Treatment on Bone Strength in Postmenopausal Women

The following article is part of conference coverage from the 2018 American Society for Bone and Mineral Research in Montreal, Canada. Endocrinology Advisor’s staff will be reporting breaking news associated with research conducted by leading experts on bone health. Check back for the latest news from ASBMR 2018 .

Vitamin D3 treatment, in doses of 2800 IU/day, have been found to improve trabecular microarchitecture and bone strength in postmenopausal women, without affecting bone mass density, according to a study presented at the American Society for Bone and Mineral Research 2018 Annual Meeting, held September 28-October 1, 2018, in Montreal, Quebec, Canada.

According to the study’s author, Lise Sofie Bislev, a PhD student at Aarhus University Hospital’s Department of Endocrinology and Internal Medicine in Denmark, the data suggest “beneficial bone effects of improving vitamin D status in postmenopausal women with low 25(OH)D levels.” Vitamin D has long been associated with bone health, but to better understand the potentially beneficial effects of vitamin D3 supplementation for postmenopausal women.

To examine these potential effects, Bislev and colleagues studied 81 postmenopausal women with low 25(OH)D levels (<20 ng/mL) who were receiving either 2800 IU/day vitamin D3 or a placebo during a period of 3 months in the wintertime. Bone health was then assessed by turnover markers, dual-energy X-ray absorptiometry (spine L1-L4, hip, forearm, and total body), high-resolution peripheral quantitative computed tomography (tibia and radius), and quantitative computed tomography (spine L1-L2 and hip) scans. The median range of these women is 65 years, and they did not use daily calcium and/or vitamin D supplements. The median dietary calcium intake of the participants was estimated to be 800 mg, and 22% were estimated to have had fractures during adulthood.

Compared with placebo, vitamin D3 supplementation increased levels of 25(OH)D and 1,25(OH) D by 230% (95% CI, 189%-272%; P <.0001) and 58% (95% CI, 190%-271%; P <.0001), respectively. Parathyroid hormone levels were reduced by 17% (−23% to −11%; P <.0001). There was a borderline (P =.07) increased osteocalcin level, but otherwise vitamin D3 supplementation had no effect on bone turnover markers. Nor was there any effect on aBMD at any site measured by dual-energy X-ray absorptiometry.

High-resolution peripheral quantitative computed tomography showed no changes in radius, but in tibia, vitamin D3 increased trabecular number (1.2% vs −0.2%; P =.04) and trabecular thickness (1.8% vs −3.2%; P <.01) and reduced trabecular separation (0.0% vs −0.1%; P =.05) compared with placebo.

Finite element analysis revealed a highly significant improvement in bone strength in the vitamin D3 group compared with placebo, assessed by failure load (1.0% vs −1.4%; P =.001) and stiffness (1.3 vs −1.7%; P =.002). Trabecular vBMD measured by quantitative computed tomography increased in the trochanter region (0.4% vs −0.6%; P =.02) and tended to increase vBMD at the total hip (P =.10) and femoral neck (P =.07). Changes in 25(OH)D correlated with failure load (r = 0.33; P =.01) and stiffness (r = 0.20; P =.07), and tended to correlate with trabecular thickness (r = 0.30; P =.07) in tibia, whereas changes in parathyroid hormone did not correlate with any of the stated measurements.

If the results of this study are accurate, as Bislev suggests, they could indicate a potentially effective new treatment for combatting bone strength deficiencies in postmenopausal women. This is an exciting new prospective treatment that may prove useful for a huge portion of the American population.

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Reference

Bislev LS, Roedbro LL, Rolighed L, Sikjaer T, Rejnmark L. Three months of vitamin D3 supplementation, 2,800 IU/d, improves trabecular bone microarchitecture and bone strength in vitamin D insufficient, hyperparathyroid women. Presented at: 2018 American Society for Bone and Mineral Research Annual Meeting; September 28-October 1, 2018; Montreal, Quebec, Canada. Abstract 0836.