The Role of Vitamin D in Menopause: Relationship to Menopausal Symptoms in Body Composition

Specific Aim 1: To compare effects of Vitamin D supplementation to usual care on symptoms in women transitioning to early postmenopause and determine the associated effect size in order to conduct a power analysis for a future RCT. Hypothesis: Vitamin D insufficient women in early postmenopause who are randomized to supplementation, titrated to achieve sufficiency for 2 months, will have fewer symptoms including hot flashes, mood, and musculoskeletal complaints than women randomized to usual care. Specific Aim 2: To compare effects of Vitamin D supplementation to usual care on body composition (by dual-energy x-ray absorptiometry \[DXA\] and by weight, BMI, waist to hip ratio) in overweight/obese women transitioning to early postmenopause and determine the associated effect size for a power analysis for a future RCT. Hypothesis: Vitamin D insufficient women in the menopausal transition randomized to supplementation, titrated to achieve sufficiency for 9 months, will improve DXA body composition (less total body and abdominal fat), compared to women in usual care, who will have increased body weight, including total and abdominal fat. Specific Aim 3: To estimate the proportion of overweight/obese middle-aged women who achieve sufficiency by 1 month versus 2 or more months and to determine if achieving sufficiency by 1 month varies by baseline characteristics. Hypothesis: About 80% of participants will achieve sufficient Vitamin D level by 1 month. Those who need more than 1 month for sufficiency will have lower baseline levels and higher initial BMI.