An 8-week vitamin D3-fortified fruit drink supplementation increases serum ferritin concentration: a randomized controlled trial in Malaysian women with low iron stores.

Background Limited randomized controlled trial (RCT) evidence supports the association between vitamin D deficiency and anemia risk, highlighting the necessity for further investigations into the role of vitamin D in influencing iron status Objective/design An 8-week double-blind RCT was carried out to determine the effect of vitamin D3-fortified fruit drink consumption (4000 IU) on vitamin D and iron status biomarkers among iron-deficient women (serum ferritin of <20 μg/L) Subjects/setting A total of 45 healthy, non-pregnant/lactating subjects aged 18-40 years [mean (SD): 25.3(4.6)] were included in the study, excluding those who donated blood 6 months prior, regularly consumed nutritional supplements, or had gastrointestinal/iron metabolic disorders. Intervention Subjects were randomly assigned to receive either vitamin D3-fortified fruit drink or a placebo Main outcome measures/statistical analyses Measurements of 25(OH)D, serum ferritin, high-sensitivity C-reactive protein (hs-CRP), and full blood counts (FBC) concentrations were taken at baseline, interim, and post-intervention, where mixed-model repeated measures ANOVA was used to analyze the intervention effect Results Attrition rate for the study was 13%, with six dropouts, while 39 subjects completed the study. Daily consumption of vitamin D3-fortified fruit drink in the intervention group resulted in significant increases in 25(OH)D and serum ferritin concentrations compared to the placebo group. The intervention group showed significantly higher mean changes in both 25(OH)D (Δ 76.4 ± 30.2 nmol/L vs Δ -1.3 ± 10.7 nmol/L, p=0.001) and serum ferritin concentrations (Δ 2.2 ± 4.2 μg/L vs Δ -0.3 ± 3.4 μg/L, p=0.048) between baseline and post-intervention. The other iron status biomarkers were not affected by the intervention. Conclusion Our study showed that daily vitamin D3-fortified fruit drink supplementation for 8 weeks effectively improved 25(OH)D and iron stores, indicated by increased serum ferritin concentrations, in iron-deficient women. Further research is needed to evaluate its safety, efficacy, feasibility, and optimal food fortification in diverse populations