Science Update

Fish oil and vitamin D supplementation helps improve outcomes in patients with gestational diabetes

According to a new study published two weeks ago in Nutrition & Metabolism, researchers demonstrated that co-supplementation of vitamin D and fish oil for 6 weeks improves biomarkers of oxidative stress and inflammation, as well as improves pregnancy outcomes in patients with gestational diabetes.

In this study, 120 patients with gestational diabetes were divided into four groups to receive either fish oil containing 180 mg EPA and 120 mg DHA twice daily with a vitamin D placebo, 50,000 IU vitamin D every 2 weeks and a fish oil placebo, 50,000 IU vitamin D every 2 weeks and the fish oil supplement twice daily, or a vitamin D placebo and fish oil placebo for 6 weeks.

As a result, patients who received co-supplementation with vitamin D and fish oil compared with vitamin D, omega-3 fatty acids and placebo given separately had significantly decreased high-sensitivity C-reactive protein, and increased total antioxidant capacity and glutathione. In addition, the vitamin D and omega-3 fatty acids co-supplementation group resulted in lower incidences of newborn hyperbilirubinemia and hospitalization.

Inositol is another nutrient that should also be considered for these women. Previous research has demonstrated that supplementation with myo-inositol and d-chiro-inositol helps to prevent gestational diabetes. Inositol acts as second messenger which regulates several hormones such as follicle stimulating hormone, thyroid stimulating hormone, and insulin.

Studies have shown that an inositol deficiency is common in women with insulin resistance. There appears to be a reduced ability to process, metabolize, and effectively use inositol from foods, which is a distinctive characteristic feature of insulin resistance. As a result, the nutritional requirements of these patients may not be met by a simple change in the diet and that inositol should be viewed as a conditionally essential nutrient in these women.

Both myo-inositol and D-chiro-inositol are essential for patients with insulin resistance. The conversion of myo-inositol to D-chiro-inositol is of interest because errors here have been strongly involved in these patients. Strong evidence supports that the body makes D-chiro-inositol from myo-inositol and more evidence suggests that some people are less able to make this conversion than others.  Along this spectrum, people who are completely unable to convert myo-inositol to D-chiro-inositol are only going to benefit from supplementation with D-chiro-inositol. Other people who make the conversion, but with less than optimal efficiency, may benefit from large doses of myo-inositol. And, other individuals in between, might see the best results from a blend of the two.


By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS

Source: Razavi M, Jamilian M et al. The effects of vitamin D and omega-3 fatty acids co-supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in patients with gestational diabetes. Nutr Metab. 2017 Dec 28;14:80. doi: 10.1186/s12986-017-0236-9.