Vitamin B complex is crucial for health, playing a key role in various metabolic processes. This group of water-soluble vitamins is essential for cell growth and metabolism. Normal muscle tone in the body depends on the vitamin B complex, which is essential for the proper functioning of the limbs, eyes, and various body parts.

The texture of the skin is also influenced by vitamin B complex. This group of vitamins is important for the functioning of the nerves and enhancing immunity.

B complex aids the body to utilise fats and carbohydrates taken (which supply energy to the body) for various functions. Thiamine (vitamin B1) is important for the metabolism of cells in the body and helps in the functioning of the nervous system.

Thiamine deficiency causes beriberi, characterised by muscle and nerve weakness, abnormal limb sensations, and calf pain. Swelling over the feet and heart failure can occur in severe cases.

Riboflavin (vitamin B2) helps in the release of energy from various nutrient substances in the body which are used by the body. Riboflavin deficiency leads to cracks around the lips, redness, and inflammation of the tongue, increased sensitivity to light, redness of pharynx, etc.

Vitamin B3 or niacin serves as a co-enzyme (substance helping main enzymes) in various metabolic activities of the body. The name niacin describes two substances—nicotinic acid and nicotinamide—both help in the metabolism of cells. Deficiency of niacin results in diarrhoea, skin problems, and even dementia in severe cases.

Pantothenic acid (vitamin B5) is another vitamin of the B complex group. It is involved in the manufacture of about 100 substances in the body including lipids, steroid hormones, and haemoglobin. Though its dietary requirement is less, it is destroyed by heat. Hence, overcooked and overheated foods become deficient in pantothenic acid, which leads to acne, indigestion, red and inflamed tongue, fatigue, and asthenia.

Pyridoxine (vitamin B6) is involved in amino acid synthesis in the body, which helps in synthesis of proteins. It also influences cognitive development, immune function, and the activity of steroid hormones in the body.

Pyridoxine deficiency leads to anaemia, burning sensation in the feet, depression, unexplained headache, and tiredness. Alcohol tends to deplete pyridoxine in the body, hence leading to a deficiency state.

Vitamin B7 or biotin plays an important role in energy metabolism in the body. It is widely present in various food substances; hence, isolated deficiency is rare in adults unless one is malnourished. But it is known to occur in children. Deficiency leads to depression, neuromuscular weakness, fatigue, and poor hair growth.

Folic acid (vitamin B9) is yet an important component of vitamin B complex, which has a vital role in making new cells in the body. Research shows that it can retard ageing. Due to folic acid deficiency, one can get anaemia, heartburn, constipation, or diarrhoea.

In pregnancy, it can cause birth defects, hence, folic acid supplements are recommended during pregnancy. Vitamin B12 (cobalamin) is closely related to folic acid and both are dependent on one another for their action. Deficiency leads to anaemia and abnormal sensations in the feet and hands, among other things. One can have paralysis of the limbs in extreme cases.

Green leafy vegetables like spinach, broccoli, cabbage, etc. provide vitamin B complex in abundant amounts. Fruits such as bananas, strawberries, raisins, and watermelon are excellent sources of vitamin B complex. This vitamin is also found in mushrooms, dairy products like cheese and yogurt, whole grains, nuts, and cereals. Among meats, liver, pork, ham, and halibut are notable sources of vitamin B complex. Vitamin B12 is one component available more in meat products.

To avoid digestive troubles, dermatitis, depression, and neuromuscular weakness, one should make sure that the diet contains an abundant amount of vitamin B complex. Substances like alcohol and tobacco should be avoided as they tend to damage nerves by depleting the vitamin B complex.

Dr Rachna Pande is a specialist in internal medicine.