Am J Clin Nutr. 2017 May 10. pii: ajcn145607.
doi: 10.3945/ajcn.116.145607. [Epub ahead of print]

Author
Purdue-Smithe AC¹, Whitcomb BW¹, Szegda KL¹, Boutot ME¹, Manson JE^2,3,4, Hankinson SE^1,2,4, Rosner BA⁵, Troy LM⁶, Michels KB^2,3,4, Bertone-Johnson ER⁷.

Author information
1. Departments of Biostatistics and Epidemiology, and.
2. Channing Division of Network Medicine and.
3. Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; and.
4. Departments of Epidemiology and.
5. Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA.
6. Nutrition, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, MA.
7. Departments of Biostatistics and Epidemiology, and ebertone@schoolph.umass.edu.

Abstract

Background
Early menopause, defined as the cessation of ovarian function before the age of 45 y, affects ∼10% of women and is associated with higher risk of cardiovascular disease, osteoporosis, and other conditions. Few modifiable risk factors for early menopause have been identified, but emerging data suggest that high vitamin D intake may reduce risk.

Objective
We evaluated how intakes of vitamin D and calcium are associated with the incidence of early menopause in the prospective Nurses' Health Study II (NHS2).

Design
Intakes of vitamin D and calcium from foods and supplements were measured every 4 y with the use of a food-frequency questionnaire. Cases of incident early menopause were identified from all participants who were premenopausal at baseline in 1991; over 1.13 million person-years, 2041 women reported having natural menopause before the age of 45 y. We used Cox proportional hazards regression to evaluate relations between intakes of vitamin D and calcium and incident early menopause while accounting for potential confounding factors.

Results
After adjustment for age, smoking, and other factors, women with the highest intake of dietary vitamin D (quintile median: 528 IU/d) had a significant 17% lower risk of early menopause than women with the lowest intake [quintile median: 148 IU/d; HR: 0.83 (95% CI: 0.72, 0.95); P-trend = 0.03]. Dietary calcium intake in the highest quintile (median: 1246 mg/d) compared with the lowest (median: 556 mg/d) was associated with a borderline significantly lower risk of early menopause (HR: 0.87; 95% CI: 0.76, 1.00; P-trend = 0.03). Associations were stronger for vitamin D and calcium from dairy sources than from nondairy dietary sources, whereas high supplement use was not associated with lower risk.

Conclusions
Findings suggest that high intakes of dietary vitamin D and calcium may be modestly associated with a lower risk of early menopause. Further studies evaluating 25-hydroxyvitamin D concentrations, other dairy constituents, and early menopause are warranted.

資料來源 : PubMed