Interplay Between Vitamin D Levels and Heavy Metals Exposure

Overview

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Key numbers

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• Q1 (high quality, low risk of bias): ≥75% “yes” responses;
• Q2 (moderate quality, unclear risk of bias): ≥50–74% “yes” responses;
• Q3 (low quality, high risk of bias): ≥50–74% “no” responses.
to formulate the research question, as detailed in Table 1, This approach provided a clear
contributed biological samples across the 14 included studies, summarized in Table 2.
Table 2. Clinical studies examining the relationships between VD and heavy metal exposure during pregnancy in mother–infant pairs.
cross-sectional study sectional (n = 391) third trimester <12 ng/mL (n = 60) MMA, showed significantly higher
Pregnancy Blood/heavy mean 25OHD level was VD levels may influence this
metals and VD (85% participants) with a 9% reduction in Cd
pregnancy cohort: a Cross- Pregnancy Third trimester Third trimester and a 3% reduction in Pb.
(34) Canada (ELISA and (n = 1649) Pb and Cd Low
bidirectional sectional (N = 3554) (87% participants) These findings suggest that
analysis (2022) (n = 1542)
25-hydroxyvitamin D Blood/VD The mean 25OHD was Sn, Tl, U, W. In particular, Pb
(36) cohort study with Cohort China of pregnancy The mean 25OHD was Se, Rb, Sr, combined exposure to these Low
(n = 598) metals Ba, Tl, Pb,
exposure to heavy Pregnancy (n = 88) Se, Cd, Sn,
(37) Cohort China (n = 244) metals (ICP-MS) First trimester As. Higher Co Medium
metals in the first Infants Oral Infants (n = 171) Hg, Tl and concentrations were
(38) concentrations at controlled Bangladesh (n = 619) heavy metals Delivery Low
(n = 33) heavy metals Concentration: with concentrations, and reduced
Pregnancy and LC-HG) All trimesters The median 25OHD Li, As
heavy metals (58% or the women) 30 nmol/L. Low VD levels
longitudinal 19% had <30 nmol/L are detrimental to both
pregnancy (2010) %Pb-S/Pb-B ratios than the
vitamin A, D and E (n = 50) (HPLC Concentrations: and Co concentrations of Cd, Cu,
95% of maternal urine samples, while Ti, Cu, As, and Se were found in 98% of samples
VD level was 26 ng/mL, with 34% of women exhibiting low levels. Additionally, mean
of 25 µg/L in blood Li levels was associated with 3.5 times higher likelihood of having VD
neonatal UCB concentrations of Pb and Cd were 6 to 7.4% higher in the VD supplementation
pregnancy ranges from 600 to 2000 IU per day, depending on baseline levels and risk factors
needs of 97.5% of the population. However, recent studies have emphasized the influence
also in various foods such as rice, vegetables, fruits, meats, and dairy products (82,83).
1. Agency for Toxic Substances and Disease Registry. Table 8-1 Regulations and Guidelines Applicable to Arsenic and Arsenic
Compounds. Toxicological Profile for Arsenic. 2007. Available online: https://www.ncbi.nlm.nih.gov/books/NBK591644/table/

Methods (brief)

(Pb), cadmium (Cd), mercury (Hg), and arsenic (As), in biological samples including maternal blood,
women and their offspring. Eligible studies included the analysis of biological samples,
risk of bias through 10 questions covering criteria such as sample selection, exposure
samples with vitamin D levels in pregnant women and infants.
628 duplicate records, 4060 unique studies were selected based on their titles and ab- of samples, biological
sample and analysis, stage of pregnancy, VD supplementation or VD concentration, heavy
taminants. Biological samples analyzed included blood, urine, meconium, and placenta.
Spectrometry (LC-MS/MS), Inductively Coupled Plasma Mass Spectrometry (ICP-MS),
and High-Performance Liquid Chromatography (HPLC). A total of 12,508 individuals
contributed biological samples across the 14 included studies, summarized in Table 2.
Ref. and Study Country Sample Biological Sam- Stage of Preg- VD Concentra- Metal/Lloid Bias (Low,
Cross- Pregnancy metals (HPLC Second and
(32) deficiency: a China and ICP-MS) Concentrations: As5+ , Also, those with VDD Low
in Chinese pregnant (LC-MS/MS) DMA concentrations of As3+ and
women (2024) and AsB) DMA compared to subjects
Ref. and Study Country Sample Biological Sam- Stage of Preg- VD Concentra- Metal/Lloid Bias (Low,
newborn (ICP-MS) All trimesters No supplementation Cu, Zn, As, neonatal VDD. Moreover,
Ref. and Study Country Sample Biological Sam- Stage of Preg- VD Concentra- Metal/Lloid Bias (Low,

Implications

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Verification notes

Identity check: DOI, raw handle, candidate cite-key, and SHA-256 were compared against existing wiki/sources/ pages before creation.
Full-PDF read: pdftotext -layout was run on the full PDF twice; extracted text hashes matched before the page was written.
Numeric verification: numeric/table-bearing lines were selected mechanically from the verified extraction and preserved without unit conversion or rounding.
Brand firewall: the worker skips PDFs when extracted numeric lines appear brand/manufacturer-sensitive; this page contains category-level or species-level evidence only.
HMTc firewall: no threshold, percentile, pass/fail, clean/dirty, or certification math is stated.

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised