Researchers combined results from four studies involving 230 pregnant women to see if taking selenium supplements could help manage gestational diabetes (high blood sugar during pregnancy). They found that taking 200 micrograms of selenium daily may help lower fasting blood sugar levels and reduce a condition called jaundice in newborns. However, selenium didn’t help improve cholesterol levels. While these results are promising, the researchers say more studies are needed to confirm these findings before making strong recommendations.

The Quick Take

  • What they studied: Whether taking selenium supplements could help pregnant women with gestational diabetes control their blood sugar and improve their cholesterol levels
  • Who participated: 230 pregnant women between ages 18-45 from four different research studies conducted between 2015-2022. All participants had gestational diabetes, which is when blood sugar becomes too high during pregnancy
  • Key finding: Taking 200 micrograms of selenium daily appeared to lower fasting blood sugar by about 5 points and reduced newborn jaundice risk by 9%, but didn’t improve cholesterol levels
  • What it means for you: If you have gestational diabetes, selenium supplements at the right dose may help with blood sugar control and protect your baby from jaundice. However, don’t start supplements without talking to your doctor first, as more research is still needed

The Research Details

This was a meta-analysis, which means researchers looked at four separate studies that had already been completed and combined all their results together. Each of the four original studies was a randomized controlled trial, which is considered the gold standard in medical research. In these trials, pregnant women were randomly assigned to either take selenium supplements or a placebo (fake pill) for 6 to 12 weeks. The selenium doses ranged from 100 to 200 micrograms per day.

The researchers carefully searched eight different medical databases to find all relevant studies published up until May 2025. Two independent reviewers checked each study to make sure it was high quality and met the inclusion criteria. They then extracted the data and combined the results using statistical methods that account for differences between studies.

By combining results from multiple studies, researchers can get a clearer picture than any single study could provide. This approach helps identify whether findings are consistent across different groups of people and different research settings. The fact that they looked at randomized controlled trials (where people are randomly assigned to groups) makes the evidence stronger than other types of studies

The studies included were relatively small (230 people total across four studies), which means the results should be interpreted cautiously. The intervention periods were short (6-12 weeks), so we don’t know if longer-term use would be safe or effective. The researchers checked for publication bias, which means they looked for evidence that only positive studies were published. The studies were conducted between 2015-2022, so they’re relatively recent

What the Results Show

When comparing the selenium group to the placebo group, selenium supplementation at 200 micrograms per day significantly lowered fasting blood sugar levels (the amount of sugar in your blood after not eating). The reduction was about 5 points on average, which is a meaningful improvement for people with gestational diabetes.

Another important finding was that selenium supplementation reduced the risk of hyperbilirubinemia (a condition where newborns have too much bilirubin, a yellow pigment that causes jaundice) in babies born to mothers taking selenium. This is significant because jaundice can be uncomfortable for newborns and sometimes requires treatment.

However, selenium supplementation did not significantly improve insulin resistance, which is how well the body uses insulin to control blood sugar. This was measured using a test called HOMA-IR. The researchers found no meaningful difference between the selenium group and placebo group on this measure.

The study looked at cholesterol levels, including total cholesterol, triglycerides (a type of fat in the blood), LDL cholesterol (often called ‘bad’ cholesterol), and HDL cholesterol (often called ‘good’ cholesterol). Selenium supplementation did not produce significant improvements in any of these cholesterol measures. This suggests that while selenium may help with blood sugar control, it doesn’t appear to help manage the fat levels in the blood during pregnancy

Previous research suggested that selenium might help improve both glucose and lipid (fat) metabolism in pregnant women with gestational diabetes. This meta-analysis partially confirms that idea—selenium does appear to help with blood sugar control, but the cholesterol findings are disappointing and don’t match earlier expectations. The finding about reduced newborn jaundice is relatively new and adds an important benefit that wasn’t previously emphasized

The main limitation is the small number of studies (only four) and relatively small total sample size (230 people). The studies were also relatively short (6-12 weeks), so we don’t know about long-term effects or safety. Different studies used slightly different doses and durations, which can make it harder to compare results. The studies were conducted in different countries with different populations, which might affect how well the results apply to everyone. Finally, some studies may have had quality issues that could affect the reliability of the findings

The Bottom Line

For pregnant women with gestational diabetes: A daily selenium supplement of 200 micrograms may help lower fasting blood sugar and reduce newborn jaundice risk (moderate confidence). However, selenium does not appear to improve cholesterol levels (high confidence). Always discuss supplementation with your healthcare provider before starting, as individual needs vary and there may be interactions with other medications or conditions

This research is most relevant to pregnant women diagnosed with gestational diabetes who are looking for additional ways to manage their blood sugar. Healthcare providers caring for pregnant women with gestational diabetes should be aware of these findings. Women without gestational diabetes should not assume these supplements are beneficial for them. Anyone with kidney disease or thyroid conditions should be especially cautious and consult their doctor

Based on the studies reviewed, the effects on blood sugar appeared within 6-12 weeks of taking the supplement. Benefits for newborn jaundice would only be apparent after delivery. However, these are relatively short timeframes, and longer-term effects remain unknown

Want to Apply This Research?

  • Track fasting blood glucose readings daily (measured first thing in the morning before eating) to see if selenium supplementation is helping your blood sugar control. Record the date, time, and reading value to identify trends over 4-6 weeks
  • If your doctor approves selenium supplementation, set a daily reminder to take your 200 microgram dose at the same time each day (such as with breakfast). Pair this habit with your existing blood sugar monitoring routine to make it easier to remember
  • Check your fasting blood glucose weekly and look for a downward trend over 6-8 weeks. Also track any symptoms of gestational diabetes like increased thirst or fatigue. Share your readings with your healthcare provider at each prenatal visit to assess whether the supplement is working for you individually

This research summary is for educational purposes only and should not replace professional medical advice. Gestational diabetes is a serious condition that requires medical supervision. Do not start, stop, or change any supplements during pregnancy without first consulting your obstetrician or healthcare provider. While this meta-analysis suggests potential benefits of selenium supplementation at 200 micrograms daily, the evidence is based on a small number of studies with limited participants. Individual results may vary, and selenium supplementation may not be appropriate for everyone. Some people may experience side effects or interactions with other medications. Your healthcare provider can help determine if selenium supplementation is right for your specific situation and can monitor your response to treatment.