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Lack of vitamin B12 affects children’s growth

- and normal B12 supplements are often not enough

Lack of vitamin B12 affects children’s growthVitamin B12 is only found in animal sources, which is why vegetarians and vegans risk getting too little. If children lack vitamin B12 it may result in underdeveloped motor skills and anemia, according to a study from Burkina Faso that is conducted in collaboration with the University of Copenhagen and Doctors Without Borders (Médecins sans Frontières). The scientists point out that vitamin B12 deficiencies are a big and overlooked problem and that normal B12 supplements are often not enough so new solutions are required.

Vitamin B12 is important for our blood formation, nervous system, and for the development of a child’s brain. B12 is found in animal food sources like meat, fish, eggs, and dairy products. Upon ingestion, the nutrient is stored in the liver. Therefore, it may take quite some time before a B12 shortage can be detected. The most common sign of a deficiency is anemia. Damage to the nervous system may also occur.
If a pregnant woman lacks vitamin B12, the deficiency is transferred to her unborn child. Subsequently, her breast milk will also contain too little vitamin B12. Lack of B12 can have a negative impact on the development of the child’s brain and motor skills. It can also affect the formation and regeneration of cells in the small intestine, which may make it difficult for the child to absorb vitamin B12 and other nutrients from the diet later in life.
In Denmark, it has been seen that children raised on vegan diets often have impaired motor skills, but this is something that can be prevented with a daily supplement of vitamin B12. In low-income countries, the problem is much greater because of inadequate healthcare and especially because people cannot afford buying animal products and vitamin B12 supplements. This was demonstrated in a study from Burkina Faso that is carried out in collaboration with the University of Copenhagen and Doctors without Borders (Médecins sans Frontières). The study results are published in the science journal PLoS Medicine.

Lack of vitamin B12 is an overlooked nutrition problem

According to Henrik Friis, a professor at the University of Copenhagen’s Department of Nutrition, Exercise and Sports, and main author of the new article, the scientists found a clear link between lack of vitamin B12, anemia, and impaired motor development in children.
When dealing with nutrition shortages in different places in the world, primarily in underdeveloped countries and low-income countries, the primary focus has been on vitamin A, iron, and zinc, whereas vitamin B12 has gotten less attention. Nonetheless, lack of vitamin B12 is one of the most overlooked nutrient shortages worldwide, and it appears that regular B12 supplements are not able to correct these shortages.

The study: Vitamin B12 supplements fail at filling up the body’s stores

In the new study from Burkina Faso, the scientists measured vitamin B12 levels in more than 1,000 children. It turned out that two thirds of the children had low or marginal levels of vitamin B12. For the following three months, the children got daily supplements of vitamin B12 as recommended by WHO. This caused levels of B12 to increase, but they dropped again when the supplementation was discontinued. Even after three months of supplementation, one third of the children still had low or marginal levels of B12 because their stores had not been properly replenished.
According to the scientists, this is because there is a limit to how much vitamin B12 the body can absorb from the small intestine. A child can only absorb around one microgram of vitamin B12 from each meal. Therefore, if a child lacks around 500 micrograms of the nutrient, it takes far more than a few weeks of supplementation to treat an acute deficiency. It would therefore be more prudent to give B12 together with several meals in order to replenish the stores faster. But this is difficult to do in low-income countries where vitamin B12 deficiencies are so widespread.

A need for new solutions

The best way to prevent vitamin B12 deficiency is by eating animal food sources or taking supplements. In many low-income countries, most people only eat what they are able to produce themselves. They cannot afford luxury foods like eggs, meat, and dairy products, even though it would be an advantage for these small households to raise their own livestock (chickens, goats, etc.). Another problem in these places is that resources are limited and their healthcare system is not all that developed. For that reason, vitamin B12 supplements are not available for the millions of people affected by a deficiency, and food enrichments programs are not an option, either. It would require an industrial expansion and new legislation to make the necessary changes. However, the scientists are in contact with UNICEF’s Supply Division in Copenhagen and hope to develop products that can help mitigate malnutrition.

  • According to UNICEF, around 200 million children worldwide below the age of five years die because of nutrient deficiencies
  • Lack of nutrients cause three million infant deaths each year
  • Lack of nutrients affects children’s physical and mental development
  • Lack of nutrients is also associated with poor immune health and a number of diseases that follow in the wake of a compromised defense system


Henrik Friis et al. Serum cobalamin in children with moderate acute malnutrition in Burkina Faso: Secondary analysis of a randomized trial. PLOS Medicine 2022

University of Copenhagen. B12 deficiency harms young children´s development – food relief not good enough. 3 May 2022

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