Environmental Glyphosate Exposure Is Associated with Lower Serum 25-Hydroxyvitamin D Concentrations: A Cross-Sectional Analysis of NHANES 2013–2018

Abstract

Simple Summary Vitamin D is essential for bone health and may also support normal immune, muscle, and metabolic function. Many adults have low vitamin D levels, but the reasons are not fully understood. Glyphosate is a widely used herbicide that people may be exposed to through food, water, or their environment. We examined whether glyphosate exposure was related to vitamin D levels in a nationally representative sample of United States adults. People with higher glyphosate concentrations in urine tended to have lower concentrations of vitamin D in their blood, even after accounting for factors known to influence vitamin D, including age, sex, body weight, season, diet, physical activity, income, and kidney function. We also found that, among participants with higher glyphosate exposure, blood vitamin D levels appeared to depend more strongly on vitamin D obtained from diet and supplements. Because this study measured exposure and vitamin D at one point in time, it cannot prove that glyphosate causes lower vitamin D levels. Nevertheless, the findings identify a possible environmental contributor to poor vitamin D status and support further prospective and experimental studies to determine whether the association is causal and to identify potential biological mechanisms.