If the body is suffering from a persistent deficiency of Vitamin B12, it is likely that this could lead to sudden irritability or possible mood changes such as mild depression (Images: Freepik) Vitamin B12 supplements are often given to people who feel constantly tired or lack energy. This nutrient plays an important role in red blood cell formation, nerve function and energy production in the body.

But what if a person falls asleep after taking the supplement? Is this normal? According to Dr RR Dutta, HOD, Internal Medicine, Paras Health, Gurugram, vitamin B12 is not commonly associated with drowsiness. In fact, the vitamin is linked to supporting energy production in the body.

“Primarily found in animal products, it plays an important role in red blood cell formation, nervous system health and DNA synthesis and helps the body produce energy,” says Dr. Dutta. He says people who feel unusually tired after taking supplements should look at other possible factors.