Vitamin B12 deficiency during pregnancy linked to increased type 2 diabetes risk

Children born to mothers who have low levels of vitamin B12 could have an increased risk of type 2 diabetes, research has claimed.
Pregnant women with deficiency of the vitamin naturally found in animal products – including fish, meat, chicke, milk and eggs – may predispose youngsters to the condition.
The study, which could prompt an overhaul of current vitamin B12 requirements for pregnant women, was presented at the Society for Endocrinology’s annual Conference in Brighton taking place this week.
Previous research has shown that mothers with low vitamin B12 levels were at greater risk of giving birth to small babies with high cholesterol and high insulin resistance, which is a risk factor for type 2 diabetes.
Now scientists from University of Warwick’s Warwick Medical School have linked changes associated with B12 deficiency to abnormal levels of a hormone called leptin that signals fullness after eating.
Lead researcher in the study, Dr Ponusammy Saravana, said: “The nutritional environment provided by the mother can permanently programme the baby’s health.
“We know that children born to under or over nourished mothers are at an increased risk of health problems such as type 2 diabetes, and we also see that maternal B12 deficiency may affect fat metabolism and contribute to this risk. This is why we decided to investigate lepti, the fat cell hormone.”
Fat cells produce leptin in response to eating food and obesity leads to consistently higher levels of the hormone, which can cause leptin resistance.
Resistance to leptin results in overeating and an increased risk of insulin resistance, which eventually leads to type 2 diabetes.
Researchers from Warwick discovered pregnancies involving women with low vitamin B12 led to babies having higher than normal levels of lepti, which could adversely programme the leptin gene.
Fellow researcher in the study, Dr Adaikala Antonysunil, said: “The leptin can increase for two reasons. Either low B12 drives fat accumulation in the foetus, and this leads to increased lepti, or the low B12 actually causes chemical changes in the placental genes that produce lepti, making more of the hormone.
“As B12 is involved in methylation reactions in the body which can affect whether genes are turned on and off, we suspect it may be the latter.”