“Overall, the associations between B-vitamins and gestational diabetes outcomes found in our study, when confirmed by further research, highlight the need to carefully evaluate and manage folate and vitamin B12 status in pregnant women,” the authors wrote in their report, due for publication in the June 2018 edition of the journal Clinical Nutrition.
According to the researchers, there have been many studies looking at the relationship between macronutrient intake, especially carbohydrates, and the risk of getting diabetes during pregnancy, also known as gestational diabetes mellitus.
“But less is known about the role of micronutrients, including B-vitamins, in influencing [this],” they added.
The study was funded by several Singaporean state-funded grants and the National Institute for Health Research. Several of the researchers have received funding from nutrition companies like Abbot Nutrition, Nestec, and Danone.
Higher B12 linked with lower odds, higher folate linked with higher odds
Their data crunch, coming from 913 pregnant women in Singapore of Chinese, Malay, or Indian heritage, suggested that higher vitamin B12 concentrations were associated with lower fasting and post-meal glucose concentrations, and lower odds of gestational diabetes mellitus.
Meanwhile, higher folate concentrations during pregnancy were associated with higher glucose concentrations after a meal and higher odds of gestational diabetes.
When high folate was coupled with low B12, it was linked to greater odds of gestational diabetes.
Based on previous studies on the nutrients, the researchers said “It has been proposed that B-vitamins, in particular folate, vitamins B6 and B12, may be involved in the pathogenesis of glucose intolerance due to their ability to regulate synthesis of [the amino acid] homocysteine, which at elevated concentrations has been linked with insulin resistance.”
They argued that the finidings have wider implications than for gestational diabetes alone. “[It] could potentially contribute to reducing pregnancy complications and adverse birth outcomes associated with having [gestational diabetes],” they wrote.
Participants in the study come from a prospective investigation of mother-offspring pairs in Singapore called the Growing Up in Singapore Towards Healthy Outcomes (GUSTO).
Recruitment took place during June 2009 and September 2010, where women less than 14 weeks pregnant were approached to participate. Researchers collected diet and lifestyle information, as well as blood samples, during a follow-up visit at 26-28 weeks of gestation.
The current data crunched in this report looked at women who provided sufficient blood for analyses of plasma folate, vitamins B6, and B12, homocysteine, and glucose, which helped the researchers reach their conclusions.
“Several limitations should be noted. First, plasma B-vitamins, homocysteine and glucose were measured at the same time, thus the causal direction cannot be established,” they added.
“Second, nutrient biomarkers may not be a direct reflection of dietary status as they are influenced by genetic and metabolic factors of individuals.”
But they argued that, in the absence of detailed information on B-vitamins supplementation, plasma concentrations prove to be advantageous over using self-reported nutrient estimates.
Source: Clinical Nutrition
Published online ahead of print, https://doi.org/10.1016/j.clnu.2017.03.022
High folate and low vitamin B12 status during pregnancy is associated with gestational diabetes mellitus
Authors: Jun S. Lai