Lack of vitamin B12 during pregnancy increases the risk of type-2 diabetes in the child

A new study reveals that children of mothers’ who lacked vitamin B12 during their pregnancy are at increased risk of metabolic diseases like type-2 diabetes. The study also shows that too little vitamin B12 may lead to abnormal levels and malfunctions of the hormone leptin, which signals satiety.

The study was presented at an endocrinology conference in Brighton, UK, and provides new information on why pregnant women are in particular need of vitamin B12, either from the diet or from supplements. Previous studies have shown that mothers with low levels of vitamin B12 generally have higher BMI (Body Mass Index) and also have a tendency to give birth to babies with lower birth weight and higher cholesterol levels. Also, children of mothers who are overweight and lack vitamin B12 during pregnancy are more likely to become insulin resistant. Insulin resistance is when the cells do not respond properly to the insulin which the body produces and have difficulty with absorbing sugar, and the condition may lead to type-2 diabetes.

The link between low vitamin B12, satiety hormone, and type-2 diabetes

In the new study, researchers from the University of Warwick took things one step further by hypothesizing that there is a link between lack of vitamin B12 and the hormone leptin, which normally sends out a signal telling us when we have had enough to eat. Leptin is produced by the fat cells in the body and influences the weight-regulating centers of the brain’s hypothalamus, by means of which it induces increased satiety and energy turnover. That way the calorie intake is inhibited and the energy expenditure increases, whereby we are able to maintain adequate fat deposits. Slim people have normal leptin levels, while overweight and obese people may have abnormally high levels of this hormone. This may lead to leptin resistance where satiety is not felt and one tends to overeat. The situation may become a vicious cycle with insulin resistance and type-2 diabetes.

Did you know that there is often a link between insulin resistance and leptin resistance?

It’s a problem that babies often have elevated leptin levels

The researchers found that babies of mothers with low levels of vitamin B12 had abnormally high leptin levels. The pregnant women’s lack of vitamin B12, the scientists claim, may lead to changes in the leptin gene and elevated concentrations of leptin in the fetus during pregnancy. It is already known that a mutation in the leptin gene in mice is responsible for hereditary mouse obesity accompanied by diabetes. In this case, the disease is caused by a flaw in the cells’ leptin receptors that interferes with leptin’s ability to affect the brain and provide the necessary feeling of satiety.

The mother’s food intake during pregnancy may affect the baby permanently

According to Dr. Ponusammy Saravanan who headed the new study, the mother’s food intake during pregnancy may have a permanent impact on the child’s health. It has been known for long that children of mothers who are either undernourished or overfed are at increased risk of health problems, and the study revealed that lack of vitamin B12 adds to that risk. The next step is a more detailed investigation of how and why the elevated leptin level is observed in children of mothers who lack vitamin B12.

Vitamin B12 is involved in switching on and off our genes

Dr. Adaikala Antonysunil, who was also in charge of the study, believes that elevated leptin levels may be caused by two factors. Either the low vitamin B12 levels cause the fetus to develop too much fat, which leads to increased concentrations of leptin. Alternatively, the low level of vitamin B12 may lead to chemical changes in the genes of the placenta that make them produce more leptin.
As it is already known that vitamin B12 is involved in certain reactions that determine which genes are switched on or off, the researchers assume that it is the second theory that causes the elevated leptin levels.

Vitamin B12 sources and causes of widespread deficiencies

Vitamin B12 is found in animal sources such as meat, fish, eggs, and dairy products. This means that many vegetarians and vegans risk becoming deficient. Bacteria in the colon are able to synthesize vitamin B12, but the amounts are often far too limited. The ability to take up vitamin B12 from food and supplements decreases with age and as a result of having too little gastric juice.
Also, overconsumption of alcohol, impaired ability to store the vitamin in the liver, and estrogens, birth control pills, sleeping medication, metformin against diabetes, and long-term use of other types of medicine may contribute to a deficiency.

Blood samples and diagnosis

A vitamin B12 deficiency can easily be detected by means of a blood sample. Lack of vitamin B12 is often seen together with low levels of folic acid.

Supplements and injections

You get the best utilization of a vitamin B12 supplement if you have sufficient stomach acid.
B12 supplements should normally be taken together with folic acid and other B vitamins that work closely together with vitamin B12. Supplements should also be taken separately from antacids and acid-neutralizing agents like baking soda. In some cases such as pernicious anemia, vitamin B12 is given as injections.

References:

University of Warwick. Maternal B12 deficiency may increase child´s risk of type-2 diabetes. ScienceDaily. November 7, 2016

Vanita R Aroda et al. Long-Term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study. Endocrine Society 2016

http://denstoredanske.dk/Krop,_psyke_og_sundhed/Sundhedsvidenskab/Ern%C3%A6ring/leptin