The Study
Effect of Vitamin D3 Supplementation on Insulin Sensitivity in Prediabetes With Hypovitaminosis D: A Randomized Placebo-Controlled Trial
This study gave some people vitamin D pills and others fake pills to see if vitamin D helped their body use sugar better. It found that those who got vitamin D did a little better at using sugar, but only in one specific test. It doesn't prove vitamin D cures or prevents diabetes — just that it might help a little in this group.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave high-dose vitamin D pills to people with prediabetes and low vitamin D levels to see if it helped their bodies use insulin better.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 577 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The improvement in insulin sensitivity is real but small — it suggests vitamin D helps the body respond better to insulin after eating, but not enough to lower long-term blood sugar markers like HbA1c yet.
- 2After 12 weeks, vitamin D levels jumped from 10.1 to 52.2 ng/mL.
- 3Insulin sensitivity improved by 15.3 units on the OGIS test, but fasting blood sugar, HbA1c, and weight didn't change much.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Cureus
Year
2020
Authors
M. M. Ahmed, U. Zingade, K. M. Badaam
Related Content
Claims (6)
In children aged 10–18 who are overweight or obese and have low vitamin D levels, taking 1000–2000 IU of vitamin D3 daily for six months lowers fasting glucose and blood pressure and increases insulin sensitivity, regardless of changes in blood vessel function or inflammation markers.
Adults with prediabetes and low vitamin D levels who take 60,000 IU of vitamin D3 once a week for 12 weeks experience a rise in their blood vitamin D levels from 10.1 ng/mL to 52.2 ng/mL, reaching sufficiency without developing high calcium levels.
In adults with prediabetes and low vitamin D levels, taking vitamin D3 supplements for 12 weeks does not reduce fasting blood sugar, HbA1c, body mass index, or standard measures of insulin resistance, but it does increase the OGIS index.
In adults with prediabetes and low vitamin D levels, taking 60,000 IU of vitamin D3 weekly for 12 weeks reduces fasting glucose levels without changing postprandial glucose, HbA1c, or body weight.
In adults with prediabetes and low vitamin D levels, taking 60,000 IU of vitamin D3 weekly for 12 weeks increases insulin sensitivity by 15.3 mL/min/m² compared to a placebo.
In adults with prediabetes and low vitamin D levels, the OGIS index changes more noticeably after vitamin D supplementation than traditional fasting blood tests like HOMA-IR or QUICKI.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.