Vitamin D Supplementation in Women

Introduction to Vitamin D Needs

The European Society for Clinical Nutrition and Metabolism (ESPEN) recommends 600-800 IU of vitamin D daily for adults 1
The American College of Sports Medicine recommends 1000-2000 IU of vitamin D daily for female athletes, depending on season and sun exposure 2, 3

Current recommendations range from 600-800 IU daily for general adults, according to the European Society for Clinical Nutrition and Metabolism (ESPEN) 1
Women over 50 require higher doses, with recommendations of 800-1000 IU daily, as suggested by the European Society for Clinical Nutrition and Metabolism (ESPEN) 1
Female athletes should aim for 1000-2000 IU vitamin D3 daily, depending on season and sun exposure, as recommended by the American College of Sports Medicine 2, 3

Approximately 40% of Europeans have vitamin D deficiency (<50 nmol/L), with 13% having severe deficiency (<30 nmol/L), according to the European Society for Clinical Nutrition and Metabolism (ESPEN) 1
21.5% of female NCAA athletes had abnormal vitamin D levels, with another study finding 80% of female athletes and dancers had abnormal values, as reported by the American College of Sports Medicine 2, 3

A standard multivitamin alone is inadequate for postmenopausal women requiring bone health optimization, who need 800-1000 IU minimum, as suggested by the European Society for Clinical Nutrition and Metabolism (ESPEN) 1
Women at high risk for osteoporosis need 400-800 IU as baseline, often more, according to the European Society for Clinical Nutrition and Metabolism (ESPEN) 4, 5
Female athletes, particularly those with limited sun exposure, need 1000-2000 IU, as recommended by the American College of Sports Medicine 2, 3

Check serum 25-hydroxyvitamin D levels to determine actual vitamin D status rather than assuming adequacy, as suggested by the European Society for Clinical Nutrition and Metabolism (ESPEN) and the American College of Sports Medicine 1, 2, 3
For women over 50 or at risk for deficiency, additional vitamin D supplementation beyond a standard multivitamin is necessary, according to the European Society for Clinical Nutrition and Metabolism (ESPEN) and the American College of Sports Medicine 1, 2, 3
Doses of 1000-2000 IU daily are safe and unlikely to cause harm in otherwise healthy adults, as reported by the European Society for Clinical Nutrition and Metabolism (ESPEN) 1
Calcium absorption is limited to 500 mg at once, so if using calcium supplements with vitamin D, spread intake throughout the day, as recommended by the American College of Sports Medicine 2, 3
Women taking 400 IU or less of vitamin D with 1000 mg or less of calcium have a small increased risk of renal stones (1 in 273 women over 7 years), according to the American College of Physicians 6

The US Preventive Services Task Force recommends against daily supplementation with 400 IU or less of vitamin D and 1000 mg or less of calcium in postmenopausal women, as these low doses have no net benefit for fracture prevention with moderate certainty, and increase kidney stone risk (Grade D recommendation) 7, 8, 9, 10
Routine prophylactic vitamin D and calcium supplementation should not be given to normal premenopausal women, and should not be given to postmenopausal women at doses of 400 IU or less of vitamin D with 1000 mg or less of calcium, as these low doses provide no fracture prevention benefit while increasing kidney stone risk 7, 8

The US Preventive Services Task Force states there is inadequate evidence about benefits and harms of higher doses of vitamin D and calcium supplementation for fracture prevention in postmenopausal women 7, 8, 11, 10
Vitamin D alone (800 IU) is recommended for fall prevention in adults ≥65 years with fall history or vitamin D deficiency 7, 12, 11, 10

The US Preventive Services Task Force recommends screening for osteoporosis rather than universal supplementation, and suggests screening all women ≥65 years for osteoporosis, and screening younger postmenopausal women whose fracture risk equals that of a 65-year-old white woman 7, 12, 13, 11, 10

The recommendation does not apply to women with diagnosed osteoporosis, women with vitamin D deficiency, women with history of osteoporotic fractures, or institutionalized women (nursing home residents) 7, 8, 10, 12