Gestational type-2-diabetes
Supplements studied for gestational type-2-diabetes.
Overview
Inositol (WA 72; medium effect size, high evidence, very high trust) has medium evidence: myo-inositol with folic acid during pregnancy may reduce gestational type-2-diabetes risk and insulin needs in at-risk women, with variable effects on birth outcomes. Nattokinase entries (WA 56) reflect soy food intake research suggesting lower GDM risk with adequate soy consumption, not nattokinase supplements directly.
Probiotics (WA 64; medium effect size, medium evidence, high trust) are possibly effective per limited evidence. Vitamin D (WA 56; low effect size, very high evidence, medium trust; 12 studies) shows mixed results for prevention and glycemic control. Iodine has insufficient evidence. The heatmap and evidence reviews below cover all six supplements.
Effect graph
Relevant supplements
Relevant supplements sorted by DEX Score.
| Inositol | ★★★★★ | Medium |
| Probiotics | ★★★★★ | Medium |
| Vitamin D | ★★★★★ | Low |
| Nattokinase | ★★★★★ | Medium |
| Iodine | ★★★★★ | Low |
| Vitamin B2 (Riboflavin) | ★★★★★ | Low |
Studies
Find individual evidence reviews for supplements sorted by DEX Score.
6 supplements for and rated at least stars. All purchase bands. No minimum star filter.
InositolView supplement →
Consider purchase·★★★★★
How we scored this▸
- In overweight adults with type 1 diabetes, taking a supplement with D-chiro-inositol and folic acid daily for six months alongside insulin therapy can help improve blood sugar control by lowering HbA1c levels.
- During pregnancy, taking myo-inositol with folic acid may reduce the risk of developing gestational diabetes and lower insulin needs for those at risk.
- It might also help reduce early births and improve some outcomes for babies, though results vary across studies.
- Lower doses of combined inositol supplements haven’t shown clear benefits in preventing gestational diabetes in women with a family history of diabetes.
- Starting inositol early in pregnancy might sometimes increase blood sugar, but more research is needed.
- For women who develop gestational diabetes, myo-inositol might help reduce how much insulin is needed, but adding D-chiro-inositol doesn’t clearly improve insulin resistance.
Browse 6 studies·1 meta-analysis
RCTEffect of dietary myo-inositol supplementation on the insulin resistance and the prevention of gestational diabetes mellitus: an open-label, randomized controlled trial2024n=100
In 200 pregnant women randomized at 11–13 weeks, myo-inositol (4,000 mg/day) improved insulin resistance and reduced gestational diabetes incidence versus control.
- Effect
- Benefit
- Duration
- 26–28 weeks
- Dose
- 4000 mg/day
- Population
- Women
- Participants
- 100
MetaInositol Nutritional Supplementation for the Prevention of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials2022n=1,321
A meta-analysis of RCTs (1,321 pregnant women) found inositol supplementation significantly reduced gestational diabetes risk versus control.
- Effect
- Benefit
- Dose
- 4 g
- Population
- Pregnant women
- Participants
- 1,321
RCTMyo-inositol supplementation to prevent gestational diabetes in overweight non-obese women: bioelectrical impedance analysis, metabolic aspects, obstetric and neonatal outcomes - a randomized and open-label, placebo-controlled clinical trial2020
In 223 overweight non-obese pregnant women, myo-inositol (2 g/day) reduced gestational diabetes incidence and improved body composition versus folic acid alone.
- Effect
- Benefit
- Dose
- 2 g
- Population
- Women
RCTDietary supplementation with myo-inositol in women during pregnancy for treating gestational diabetes2016n=142
In pregnant women with gestational diabetes, myo-inositol supplementation improved glycemic control during pregnancy versus control in a clinical trial.
- Effect
- Benefit
- Population
- Women
- Participants
- 142
RCTMyo-inositol may prevent gestational diabetes in PCOS women2012n=46
In 98 pregnancies among women with PCOS, myo-inositol during pregnancy was associated with lower gestational diabetes rates than metformin stopped after conception.
- Effect
- Benefit
- Duration
- 3 years
- Population
- Women
- Participants
- 46
RCTThe effect of myoinositol supplementation on insulin resistance in patients with gestational diabetes2011
In women with gestational diabetes over 8 weeks, myo-inositol (4 g/day) improved insulin resistance markers versus control.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 4 g/day
- Population
- Women
ProbioticsView supplement →
Consider purchase·★★★★★
How we scored this▸
- Probiotics are possibly effective for Gestational diabetes.
Browse 1 study·1 meta-analysis
MetaProbiotics for the prevention of gestational diabetes mellitus: A meta-analysis of randomized controlled trials2024n=3,527
A meta-analysis of 14 pregnancy RCTs (n=3527) found probiotics reduced gestational diabetes incidence (RR 0.71) mainly in women with BMI <26 kg/m² and age <30 years.
- Effect
- Benefit
- Population
- Women
- Participants
- 3,527
NattokinaseView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Eating enough soy foods including natto during pregnancy may lower the chance of developing gestational diabetes, a type of diabetes that occurs during pregnancy.
- A recent study found that pregnant women who ate less than 40 grams of soy daily were more likely to develop this condition.
- Soy might also help with blood sugar and metabolism in women who already have gestational diabetes.
- Including soy foods as part of a healthy diet in pregnancy could be beneficial.
Browse 2 studies
ObservationalThe association between soy intake and risk of gestational diabetes mellitus: a prospective cohort study2021n=224
In 224 Chinese pregnant women, soy intake below vs above 40 g/day was examined for gestational diabetes risk; higher intake showed no significant association with GDM in adjusted analysis.
- Effect
- Benefit
- Dose
- 40 g/day
- Population
- Women
- Participants
- 224
RCTThe Effect of Soy Intake on Metabolic Profiles of Women With Gestational Diabetes Mellitus2015n=34
In 68 women with gestational diabetes, a soy diet (35% soy protein) for 6 weeks lowered fasting glucose, insulin, and HOMA-IR and raised insulin sensitivity vs a 70% animal-protein control diet.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 0.8 g/kg/day protein (35% soy)
- Population
- Women
- Participants
- 34
Vitamin DView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Research on vitamin D for gestational diabetes (GDM) shows mixed results.
- Some studies suggest taking vitamin D during pregnancy improves blood sugar control, insulin levels, and cholesterol.
- Vitamin D might also lower the chances of babies being born early or needing hospital care.
- However, other studies found taking vitamin D does not prevent gestational diabetes.
- Vitamin D works best when paired with other nutrients like calcium.
- Overall, the ideal vitamin D level during pregnancy to reduce GDM risk seems to be in a middle range, not too low or too high.
Browse 12 studies·4 meta-analyses
MetaInfluence of vitamin D-calcium on metabolic profile for gestational diabetes: a meta-analysis of randomized controlled trials2024
A meta-analysis of 5 RCTs (306 pregnant women with gestational diabetes) found vitamin D-calcium co-supplementation lowered fasting glucose, HbA1c, and LDL versus control.
- Effect
- Benefit
- Population
- Women
MetaVitamin D supplementation for women during pregnancy2024n=1,368
An updated Cochrane review of 10 RCTs (2,313 pregnant women) found vitamin D alone may reduce severe postpartum hemorrhage and low birthweight, but evidence was low to very low certainty.
- Effect
- Benefit
- Population
- Women
- Participants
- 1,368
RCTEffect of vitamin D supplementation on glucose control in mid-late gestation: A randomized controlled trial2023n=862
In a multicenter RCT of 1,720 pregnant women, 1,600 IU/day vitamin D3 from 24–28 weeks prevented the fasting glucose rise seen with 400 IU/day at delivery (between-group difference −0.2 mmol/L).
- Effect
- Benefit
- Duration
- 2 months
- Dose
- 1600 IU/day
- Population
- Women
- Participants
- 862
MetaEffect of Vitamin D Supplementation on Serum 25-Hydroxyvitamin D and Homeostatic Model of Insulin Resistance Levels in Healthy Pregnancy: A Systematic Review and Meta-Analysis2023n=380
A meta-analysis of 4 studies (380 non-diabetic pregnant women) found vitamin D supplementation raised 25(OH)D and reduced HOMA-IR, with greater insulin sensitivity benefit at higher weekly doses.
- Effect
- Benefit
- Population
- Women
- Participants
- 380
MetaVitamin D Supplementation for the Outcomes of Patients with Gestational Diabetes Mellitus and Neonates: A Meta-Analysis and Systematic Review2023
A meta-analysis of 20 RCTs (1,682 gestational diabetes patients) found vitamin D supplementation improved lipid profiles and reduced adverse neonatal outcomes.
- Effect
- Benefit
- Dose
- 682 g/day
- Population
- Women
MetaMaternal vitamin D status and risk of gestational diabetes mellitus: A systematic review and meta-analysis of prospective cohort studies2021
A meta-analysis of 27 prospective studies found maternal vitamin D deficiency increased gestational diabetes risk by 26% (OR 1.26); lowest risk was at serum levels of 40–90 nmol/L.
- Effect
- Benefit
RCTThe effect of combined supplementation with vitamin D and omega-3 fatty acids on blood glucose and blood lipid levels in patients with gestational diabetes2021n=150
In 150 women with gestational diabetes, combined vitamin D and omega-3 fatty acids for 6 weeks lowered fasting glucose, insulin, HOMA-IR, and lipids versus placebo.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 40000 IU/day
- Population
- Women
- Participants
- 150
- Ages
- 18–40
RCTThe effects of vitamin D and omega-3 fatty acid co-supplementation on glycemic control and lipid concentrations in patients with gestational diabetes2017n=35
In a 6-week RCT of 140 gestational diabetes patients, combined vitamin D and omega-3 fatty acids lowered fasting glucose, insulin, HOMA-IR, and triglycerides more than either alone or placebo.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 50000 IU/day
- Population
- Women
- Participants
- 35
RCTEffect of various doses of vitamin D supplementation on pregnant women with gestational diabetes mellitus: A randomized controlled trial2016n=38
In a RCT of 133 pregnant women with gestational diabetes, high-dose vitamin D (50,000 IU every 2 weeks) improved insulin resistance and antioxidant capacity versus lower doses or placebo.
- Effect
- Benefit
- Duration
- 25 days
- Population
- Women
- Participants
- 38
RCTEffects of vitamin D supplementation on metabolic indices and hs-CRP levels in gestational diabetes mellitus patients: a randomized, double-blinded, placebo-controlled clinical trial2016n=38
In a 2-month RCT of 76 gestational diabetes patients, 50,000 IU vitamin D3 every 2 weeks lowered fasting glucose and HbA1c versus placebo but did not change lipids or hs-CRP.
- Effect
- Benefit
- Duration
- 2 months
- Dose
- 50000 IU/day
- Population
- Women
- Participants
- 38
- Ages
- 15–45
RCTVitamin D3-Supplemented Yogurt Drink Improves Insulin Resistance and Lipid Profiles in Women with Gestational Diabetes Mellitus: A Randomized Double Blinded Clinical Trial2016
In pregnant women with gestational diabetes, daily vitamin D3-fortified yogurt for 16 weeks improved insulin resistance and lowered triglycerides, total cholesterol, and LDL versus plain yogurt.
- Effect
- Benefit
- Duration
- 16 weeks
- Population
- Women
- Ages
- 24–32
RCTThe efficacy and safety of a high dose of vitamin d in mothers with gestational diabetes mellitus: a randomized controlled clinical trial2012n=45
In a 3-month RCT of 45 newly diagnosed gestational diabetes patients, a single 300,000 IU intramuscular vitamin D dose raised serum 25(OH)D by 158% and lowered PTH versus control.
- Duration
- 3 months
- Dose
- 300000 IU/day
- Population
- Women
- Participants
- 45
- Avg age
- ~31
IodineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- There is not enough evidence to know whether iodine helps with gestational diabetes.
Browse 1 study·1 meta-analysis
MetaEffects of iodine supplementation during pregnancy on pregnant women and their offspring: a systematic review and meta-analysis of trials over the past 3 decades2020
A meta-analysis of pregnancy iodine trials found supplementation improved maternal iodine status, with mixed effects on infant growth and neurodevelopment outcomes.
- Effect
- Benefit
- Population
- Women
Vitamin B2 (Riboflavin)View supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if taking riboflavin (vitamin B2) supplements during pregnancy lowers the chance of gestational diabetes.
- One large study in mostly Chinese pregnant women found that those taking more than 2.5 mg of riboflavin in the first trimester and more than 2.1 mg in the second trimester had a lower risk of gestational diabetes compared to those taking less than 1.1 mg.
- Eating riboflavin-rich foods did not show this effect.
- The results may not apply to all populations.
Browse 1 study
Clinical trialPregnancy thiamine and riboflavin intake and the risk of gestational diabetes mellitus: A prospective cohort study2023
A study in women found that higher intake of thiamine and riboflavin during pregnancy is associated with a lower incidence of GDM.
- Effect
- Benefit
- Duration
- 24–28 weeks
- Population
- Women
Evidence visualised
Same ratings as above, aggregated so you can see coverage and imbalance.
| Supplement | DEX | Studies | Meta-analyses | Share |
|---|---|---|---|---|
| Vitamin D | ★★★★★56% | 12 | 4 | 52% |
| Inositol | ★★★★★72% | 6 | 1 | 26% |
| Nattokinase | ★★★★★56% | 2 | 0 | 9% |
| Iodine | ★★★★★48% | 1 | 1 | 4% |
| Probiotics | ★★★★★64% | 1 | 1 | 4% |
| Vitamin B2 (Riboflavin) | ★★★★★40% | 1 | 0 | 4% |