Trial reportNutrition journal2016
Effect of vitamin D3 supplementation on iron status: a randomized, double-blind, placebo-controlled trial among ethnic minorities living in Norway.
Trial report in Nutrition journal, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
17 citing papers in PubMed, 2 syntheses or guidelines pooled it, 34 citations in OpenAlex.
- Effectiveness of Dietary Interventions to Treat Iron-Deficiency Anemia in Women: A Systematic Review of Randomized Controlled Trials.Nutrients · 2022Pooled it
- The effect of vitamin D supplementation on hemoglobin concentration: a systematic review and meta-analysis.Nutrition journal · 2020Pooled it
- Effect of supplementation with vitamin D on biochemical markers of iron status and erythropoiesis in older people: BEST-D trial.The British journal of nutrition · 2025Trial
- Effects of Vitamin D Supplementation on Haematological Values and Muscle Recovery in Elite Male Traditional Rowers.Nutrients · 2018Trial
- Vitamin D Supplementation Modestly Reduces Serum Iron Indices of Healthy Arab Adolescents.Nutrients · 2018Trial
- High-Dose Vitamin DJPEN. Journal of parenteral and enteral nutrition · 2018Trial
- Randomized supplementation of 4000 IU vitamin DNutrition journal · 2017Trial
- Comparative analysis of two analytical methodologies for deriving dietary patterns associated with vitamin D insufficiency and anemia among expectant mothers.International journal of medical sciences · 2026Article
- Serum Vitamin D Levels and Risk of Iron Deficiency Anemia in Adults: A Cross-Sectional Study and Mendelian Randomization Analysis.Food science & nutrition · 2025Review
- Maternal prenatal, with or without postpartum, vitamin D3 supplementation does not improve maternal iron status at delivery or infant iron status at 6 months of age: secondary analysis of a randomised controlled trial.BMJ nutrition, prevention & health · 2023Article
- Article
- The Association Between Ferritin and Vitamin D Levels in Premenopausal Fibroid Uterus Cases With Anemia.Cureus · 2021Article
- Vitamin D deficiency and anemia is highly prevalent and dependent on the etiology of heart failure: A pilot study.Cardiology journal · 2021Article
- The association between iron and vitamin D status in Arab adolescents.Public health nutrition · 2020Article
- The Effect of Serum 25-Hydroxyvitamin D on Serum Ferritin Concentrations: A Longitudinal Study of Participants of a Preventive Health Program.Nutrients · 2019Article
- Article
- Vitamin D Status Is Associated with Hepcidin and Hemoglobin Concentrations in Children with Inflammatory Bowel Disease.Inflammatory bowel diseases · 2017Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundBoth vitamin D and iron deficiencies are widespread globally, and a relationship between these deficiencies has been suggested. However, there is a paucity of randomised controlled trials assessing the effect of vitamin D supplementation on iron status. PURPOSE: We aimed to investigate whether 16 weeks of daily vitamin D3 supplementation had an effect on serum ferritin, haemoglobin, serum iron and transferrin saturation.
methodsOverall, 251 participants from South Asia, Middle East and Africa aged 18-50 years who were living in Norway were randomised to receive daily oral supplementation of 10 μg vitamin D3, 25 μg vitamin D3, or placebo for 16 weeks during the late winter. Blood samples from baseline and after 16 weeks were analysed for serum 25-hydroxyvitamin D (s-25(OH) D), serum ferritin, haemoglobin and serum iron. In total, 214 eligible participants completed the intervention (86 % of those randomised). Linear regression analysis were used to test the effect of vitamin D3 supplementation combined (10 or 25 μg) and separate doses 10 or 25 μg compared to placebo on change (T2-T1) in each outcome variable adjusted for baseline s-25(OH)D values.
resultsThere was no difference in change in the levels of s-ferritin (1.9 μg/L, 95 % CI: -3.2, 7.0), haemoglobin (-0.02 g/dL, 95 % CI: -0.12, 0.09), s-iron (0.4 μg/L, 95 % CI: -0.5, 1.3) or transferrin saturation (0.7 %, 95 % CI: -0.6.1, 2.0) between those receiving vitamin D3 or those receiving placebo. Serum 25-hydroxyvitamin D increased from 29 nmol/L at baseline to 49 nmol/L after the intervention, with little change in the placebo group.
conclusionsIn this population of healthy ethnic minorities from South Asia, the Middle East and Africa who had low vitamin D status, 16 weeks of daily supplementation with 10 or 25 μg of vitamin D3 did not significantly affect the haemoglobin levels or other markers of iron status.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.