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United States Department of Agriculture

Agricultural Research Service

Research Project: MUSCULOSKELETAL HEALTH IN THE ELDERLY

Location: Human Nutrition Research Center on Aging

Title: Changes in vitamin D metabolites during teriparatide treatment

Authors
item Cosman, Felicia -
item Dawson-Hughes, Bess -
item Wan, Xiaohai -
item Krege, John H. -

Submitted to: Bone
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 29, 2012
Publication Date: June 1, 2012
Citation: Cosman, F., Dawson-Hughes, B., Wan, X., Krege, J. 2012. Changes in vitamin D metabolites during teriparatide treatment. Bone. 50(6):1368-1371.

Interpretive Summary: Parathyroid hormone (PTH) stimulates the conversion of 25-hydroxyvitamin D to its active form, 1,25-dihydroxyvitamin D. PTH is used as therapy to lower risk of fractures in subjects at high risk for fracture. Vitamin D is important for bone health, and the question arises as to whether subjects receiving PTH therapy may have a higher vitamin D requirement. The effect of treatment with PTH on 25-hydroxyvitamin D levels was examined in 336 women and 287 men who were treated with PTH or placebo. All subjects received 400 to 1200 IU per day of supplemental vitamin D. After one year of PTH treatment, the women had a 19% decrease and the men an 11% decrease in serum 25-hydroxyvitamin D level. Serum 25-hydroxyvitmain D changes in the placebo group were not significant. An area of potential investigation would be to assess whether subjects being treated with PTH would benefit from higher doses of vitamin D.

Technical Abstract: The objective was to assess changes in serum 1,25(OH)2D and 25(OH)D concentrations during teriparatide 20 g/day (teriparatide) therapy in the double-blind Fracture Prevention Trial of postmenopausal women with osteoporosis and male study of men with osteoporosis. Patients were randomized to teriparatide or placebo, and received daily supplements of calcium 1000 mg and vitamin D 400-1200 IU. Serum 1,25(OH)2D measured in a subset, and serum 25(OH)D measured at baseline and 12 months. In women (N=336), median 1,25(OH)2D concentrations at 1 month increased by 27% (P<0.0001) in the teriparatide group versus -3% (P=0.87) in the placebo group (P<0.0001). At 12 months, the increase was 19% (P<0.0001) in the teriparatide group versus -2% (P=0.23) in the placebo group (between group P<0.0001). Median 25(OH)D concentrations at 12 months decreased by 19% (P<0.0001) in the teriparatide group versus 0% (P=0.13) in the placebo group (P<0.0001). In men (N=287), median 1,25(OH)2D concentrations at 1 month increased by 22% (P<0.0001) in the teriparatide group versus 0% (P=0.99) in the placebo group (between group P<0.0001). At 12 months, the increase was 14% (P<0.0001) in the teriparatide group versus 5% (P=0.004) in the placebo group (P=0.17). Median 25(OH)D concentrations at 12 months decreased by 11% (P=0.001) in the teriparatide group. Treatment with teriparatide increased 1,25(OH)2D and decreased 25(OH)D.

Last Modified: 8/22/2014