Vitamin D2026-05

Associations between urinary arsenic and vitamin D deficiency: a cross-sectional analysis of NHANES 2011-2018.

Zhou Meiling, Liu Yiyun, Liu Wenqi, Zhang Yunwei — Journal of health, population, and nutrition

Summary

A study looked at the connection between arsenic exposure and vitamin D levels in US adults. It found that people with higher levels of arsenic in their urine were more likely to have a vitamin D deficiency. This suggests a potential link, but more research is needed to understand if one causes the other.

AI-generated summary — read the original

Key points

Higher arsenic levels in urine were associated with an increased likelihood of vitamin D deficiency.
This link was observed in a large study of US adults.
The association varied among different groups of people, such as women and younger adults.
More research is needed to determine if arsenic exposure directly causes vitamin D deficiency.

What the study looked at

**What question the study asked:** This study aimed to understand if there is a connection between exposure to arsenic and having low vitamin D levels among adults in the United States. While both are known to affect health, their combined impact hasn't been widely explored. **How it was studied:** Researchers analyzed health data from 6,148 U.S. adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2018. They looked at measurements of arsenic in participants' urine and their blood vitamin D levels, along with other health and lifestyle information. This type of study observes existing data at a single point in time. **What it found:** The study found that adults with higher levels of arsenic in their urine were more likely to have a vitamin D deficiency. This association was particularly noticeable in certain groups, such as women and adults under 60. However, for individuals with conditions like stroke or sleep disorders, the association appeared to be the opposite, possibly because these individuals were already taking vitamin D supplements. It's important to remember that this study shows an association, not that arsenic directly causes vitamin D deficiency.

Dietary takeaway

While this study suggests a link between arsenic exposure and vitamin D deficiency, it doesn't mean that changing your diet alone will prevent or reverse this. However, ensuring adequate vitamin D intake through fortified foods like milk and cereals, fatty fish, or sun exposure remains important for overall health. Remember, this is one observational study, and more research is needed to understand the exact relationship and how it might impact dietary recommendations.

Abstract

Arsenic exposure and vitamin D deficiency independently contribute to adverse neurological and systemic outcomes, yet their interplay in the general population has not been thoroughly characterized. We investigated the association between urinary arsenic (total arsenic and dimethylarsinate [DMA]) and vitamin D deficiency and explored how this relationship varies by demographic, behavioral, laboratory, dietary, and neurological comorbidity factors. Using data from 6,148 U.S. adults aged ≥ 18 years in NHANES 2011-2018, we estimated odds ratios (ORs) for deficiency per interquartile‑range increase in each arsenic measure using survey-weighted logistic regression. After full adjustment for demographics, lifestyle, dietary, and clinical factors, the ORs for total urinary arsenic and DMA were 1.30 (95% CI 1.16, 1.45) and 1.50 (95% CI 1.27, 1.78), respectively. Associations were strongest among women; adults aged < 60 years; Non‑Hispanic, highly educated, underweight individuals; as well as current smokers and drinkers. In contrast, participants with stroke or sleep disorders exhibited inverse associations, likely due to routine clinical vitamin D supplementation. These findings demonstrate a robust, dose‑dependent association between arsenic exposure and vitamin D deficiency in U.S. adults. They suggest the importance of integrated public health strategies-combining arsenic mitigation with targeted vitamin D strategies-and highlight the need for longitudinal and interventional studies to establish causality and to determine whether optimizing vitamin D status might potentially modify the adverse health effects of arsenic.

View on PubMed →DOI: 10.1186/s41043-025-01235-0