Association of dietary nutrient intake with reproductive lifespan in women: a cross-sectional analysis using weighted quantile sum regression in NHANES 2001–2018

The female reproductive lifespan, defined as the period from menarche to natural menopause, is a critical determinant of ovarian reserve and long-term health outcomes in women. Although nutritional factors are recognized as modifiable regulators of reproductive aging, comprehensive evidence regarding the role of specific dietary nutrients, both individually and in combination, remains limited. This study aimed to investigate the associations between dietary nutrient intake and reproductive lifespan among naturally menopausal women. The data were collected from 4,782 U.S. women in NHANES (2001–2018). Dietary nutrient intake was assessed via one or two 24-hour dietary recall interviews, and the usual intake was derived using the Multiple Source Method (MSM). Reproductive lifespan was calculated as the difference between self-reported ages at menarche and natural menopause. Weighted linear regression and the weighted quantile sum (WQS) model were applied to evaluate individual and combined impacts on reproductive lifespan. Restricted cubic spline (RCS) models were used to examine potential nonlinear associations between nutrient intake and reproductive lifespan. After adjusting for covariates and controlling for multiple testing using false discovery rate (FDR) correction, copper intake was robustly associated with longer reproductive lifespan (P < 0.001, P-FDR < 0.001). RCS models revealed significant non-linear relationships between sodium, iron, vitamin A, vitamin E, and reproductive lifespan. Importantly, the WQS model revealed a significant positive association of the dietary nutrient mixture with reproductive lifespan, with vitamin B2, vitamin C, total polyunsaturated fatty acids, copper, calcium, selenium, and beta-carotene identified as the major contributors. Our findings suggest that optimizing the intake of key dietary nutrients may represent a promising strategy to support a longer reproductive lifespan in women.