Overview
Schwalfenberg and colleagues bought every prenatal vitamin product they could find in Edmonton, Canada (26 products, 51 lots) and measured mercury, arsenic, lead, cadmium, aluminum, nickel, titanium and thallium by ICP-SFMS. Results are expressed as micrograms per recommended daily dose and compared with California Proposition 65 and US Pharmacopeia daily limits. Arsenic was speciated in the four samples with the highest total arsenic.
Key numbers
- Lead: average 0.535, minimum 0.124, maximum 4.002 µg per daily dose; 14 of 26 products above the 0.5 µg/day Proposition 65 level (Table 2).
- Cadmium: average 0.373, maximum 0.975 µg/day; total arsenic: average 0.421, maximum 2.208 µg/day (Table 2).
- Inorganic arsenic in the four speciated samples: 3 of 4 above 0.1 µg/day, one at 0.4 µg/day (Section 3.2.4).
- Mercury: average 0.012, maximum 0.099 µg/day (Table 2).
Methods (brief)
Solid products were microwave-digested in nitric acid, hydrogen peroxide and hydrofluoric acid; liquids were diluted. Analysis by sector-field ICP-MS with internal standardization; arsenic species by anion-exchange HPLC with hydride generation ICP-MS. Digestion blanks and matrix-matched CRMs were run, but recoveries and detection limits are not reported.
Evidence Fitness
A convenience sample from one city with 51 analyzed lots. Values are per daily dose, not per kilogram, so they cannot be compared directly with concentration bands. Table 2 and the text disagree on the mercury detection count and the nickel average. These are finished prenatal supplements, so for the vitamin-mineral-premix page this is a proxy (finished product, not the premix ingredient) and that page is not linked.
Related evidence
- Ingredient class — vitamin/mineral (single, multi-mineral, multi-vitamin/mineral)
- Lead
- Cadmium
- Arsenic
- Mercury
Update history
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