Supplements of 20 microg/d cholecalciferol optimized serum 25-hydroxyvitamin D concentrations in 80% of premenopausal women in winter.

The serum 25-hydroxyvitamin D [25(OH)D] response to daily supplementation with 20 microg cholecalciferol (D3) during winter in predominantly white premenopausal women living in Maine was measured and the effects of body composition and hormonal contraceptive use on baseline serum 25(OH)D concentrations and the response to supplementation were examined. A total of 112 women (22.2 +/- 3.

Correction of preoperative vitamin D deficiency after Roux-en-Y gastric bypass surgery.

Background: To evaluate the adequacy of supplementation to correct preoperative vitamin D deficiency in adult patients during the year after Roux-en-Y gastric bypass (RYGB) surgery.

Methods: The medical records were reviewed and the preoperative and 12-month postoperative serum 25-hydroxyvitamin D [25(OH)D] levels were compared in patients who underwent RYGB from 2002 to 2004. The serum 25(OH)D levels were defined as being optimal (> or = 80 nmol/L), suboptimal (50-79 nmol/L), or deficient (<50 nmol/L).

Adolescent girls in Maine are at risk for vitamin D insufficiency.

The objective was to determine the seasonal fluctuations in serum 25-hydroxyvitamin D (25-OHD) in a group of healthy adolescents living in a northern climate. Twenty-three 9- to 11-year-old girls participated in the study from September 2000 to March 2003. Serum 25-OHD and parathyroid hormone levels were measured each September and March.