B vitamins are vital for health

The human body cannot accumulate these vitamins in large quantities, therefore their regular intake with food is necessary. The main sources are animal products, dairy products, eggs, legumes, nuts, cereals, green vegetables, and fortified grain products, including cereals.

For most people, a balanced diet is enough to cover the daily requirement. However, there are groups of the population who may need additional vitamin intake. These include the elderly, who have a reduced ability to absorb vitamin B12, as well as vegans, pregnant women, and those who have undergone gastric bypass surgery. In these cases, supplements with B12 may be necessary because herbal products do not contain cobalamin. At the same time, the standard dose of the supplement — about 2.4 micrograms of vitamin B12 per day — usually covers the need.

It is also worth considering that some common medications, such as metformin (used for diabetes) and proton pump inhibitors (such as omeprazole), may reduce the absorption of B12. This creates an additional risk of deficiency for those who regularly take such drugs.

However, in the case of B vitamins, it is important to take precautions. As Dr. Joel Mason, a gastroenterologist and lead scientist at the Tufts University Center for the Study of Nutrition for the Elderly, warns, an excess of certain vitamins can be toxic. A striking example is vitamin B6. In the 1980s, it was widely taken in large doses to relieve premenstrual pain. Although the recommended daily dose is about 2 mg for men and 1.6 mg for women, some women took up to 200 mg per day, which led to irreversible nerve damage (peripheral neuropathy).

Another example is niacin (B3), which is used in high doses to lower cholesterol levels. However, this approach can cause side effects, including severe redness of the skin, itching and rash.

B vitamins play a special role during pregnancy. Since the 1940s, corn, rice, and wheat flour, which contain B1, B2, and B3, have been subjected to mandatory enrichment in the United States. And since 1998, folic acid (a synthetic form of folate, vitamin B9) has been added to them to reduce the risk of neural tube defects in the developing fetus. This is especially important because the neural tube is formed in the first weeks after conception — often even before a woman finds out about her pregnancy. Due to the massive fortification of flour with folic acid in the United States, the incidence of these birth defects decreased by about 70%.

However, excess folic acid can also carry risks. Research by Tufts scientists has shown that too much folic acid intake can stimulate the growth of cancer cells, especially if mutated or precancerous cells are already present in the body. After all, folate is like a fertilizer for cells, and its excess can promote faster division and growth of potentially malignant cells. However, it is important to note that such cases are rather an exception.: They are observed mainly in people who take several sources of folic acid at once in high doses. In general, normal folate intake reduces the risk of developing diseases such as colon, pancreatic, and possibly breast cancer in women after menopause.

One of the little-known but serious problems is thiamine (B1) deficiency in people who have undergone bariatric surgery. In the past, this deficiency was more common in people with alcohol dependence, but now it is increasingly being detected in patients after gastric bypass surgery. Symptoms include weakness, confusion, visual disturbances, and even a life—threatening condition called beriberi disease, which can cause permanent damage to the brain and nervous system. It is important that emergency physicians and surgeons recognize these signs and administer thiamine in a timely manner, even before receiving test results.