Multinutrient Supplementation Improves Selenium and Iodine Status But Has No Clear Impact on Iron and Zinc in Apparently Healthy Vegans

Several minerals are regarded critical in vegan diets, due to lower contents or bioavailability in plant foods. The MultiVeg study evaluated the mineral status of healthy vegans before and after a 16-week period taking a multinutrient supplement, with a special focus on selenium in this analysis. This randomized, double-blind, placebo-controlled trial was conducted in Germany and assessed mineral biomarkers in blood and urine. Data were collected at baseline and follow-up via study center visits and online surveys. The study was conducted with 72 adult vegans (aged from 19 to 57 years). The intervention group received a daily multinutrient supplement containing sodium selenite (70 μg), potassium iodide (150 μg), iron bisglycinate (7 mg), and zinc bisglycinate (6 mg), and the control group received a placebo. The status of iron, zinc, iodine, and selenium was assessed. Between-group differences were assessed with one-way analysis of covariance. Compared with the control, multinutrient supplementation significantly improved selenium status (selenoprotein P: mean ± SD, 15 ± 9 μg/L vs 1 ± 6 μg/L; P < .001) and iodine status (urinary iodine excretion: median [interquartile range], 90 [102] μg/g creatinine vs 15 [46] μg/g creatinine; P < .001). No significant between-group differences were observed for changes in hemoglobin, ferritin, soluble transferrin receptor, or whole-blood zinc concentrations. These results suggest that the tested supplement effectively increased the selenium and iodine status in apparently healthy vegans. Generally, iron and zinc statuses were already within the reference ranges, and supplementation had no clear effect on iron or zinc status. In conclusion, moderate selenium and iodine supplementation may be beneficial for vegans in Germany.