B complex (B-group, B Vitamins) is not a single vitamin. It consists of eight B vitamins viz. B1, B2, B3, B5, B6, B7, B9, and B12. These vitamins are often found together in food items. They have similar chemical structure and functions.
These water soluble vitamins are essential for proper functioning of body. Their deficiency directly affects metabolism and causes many diseases. B vitamins works as co enzymes in production of energy. They are also required for production of RBCs, protein synthesis, tissue repair and maintenance.
Each B vitamin perform specific functions and as a whole supports proper functioning of body. Every body organ needs at least one form of vitamin B. Since these vitamins are water soluble, they are not stored but excreted outside the body by the kidney in urine. Therefore, body needs daily supply of these vitamins through healthy diet. Many of B-complex vitamins are found in same food like in whole grains, yeast, dry foods, milk, and fresh fruits and vegetables.
Why B-complex is required in body?
- These vitamins are required for proper metabolism. Their deficiency can cause poor metabolism and weight gain.
- They are required for breakdown of food and releasing of energy.
- They improves appetite, energy, muscle tone, memory and skin health.
- They are beneficial in reducing stress, anxiety, and irritability.
- They are required for healthy skin. Intake of B-complex prevents cracks at the corner of mouth, oily skin, flaky skin, wrinkling, patchy discoloration, acne, dull skin, redness around the nostrils.
- The deficiency of B vitamin can cause hair fall and alopecia.
- B-complex is required by every organ of the body i.e. brain, heart, eyes, digestive system, hormones, skin, hair, liver and kidneys.
- The deficiency of B complex results in many diseases.
The 8 vitamins of B complex
Vitamin B1 (Thiamin)
Vitamin B1 or Thiamin functions as the co-enzyme thiamin pyrophosphate (TPP) in the metabolism of carbohydrates and branched-chain amino acids. It is essential for glucose metabolism in the body.
B1 is also required for proper functioning of all cells and nerves of body, normal appetite and memory.
Due to deficiency of thiamin, there is decrease in carbohydrate and amino acid metabolism.
The deficiency of Vitamin B1 or Thiamin causes Beri-beri (affects the cardiovascular, muscular, gastrointestinal and nervous systems), polyneuritis, and Wernicke-Korsakoff syndrome (involuntary movement of the eyeball, paralysis of the eye muscle, staggering and mental confusion).
Good sources of thiamin, include whole meal cereal grains, seeds (especially sesame seeds), legumes, wheat-germ, nuts, and yeast.
Vitamin B2 (Riboflavin)
Vitamin B2 or Riboflavin functions as the co-enzyme in numerous oxidation and reduction reactions. It is required to release the energy from food. It supports proper growth and development.
It is needed for good vision and healthy skin.
Its deficiency causes sore throat, oedema of the pharyngeal and oral mucous membranes, painful-smooth- purple-red tongue, cracks and redness in the tongue and corners of the mouth, anxiety, inflamed eyelids, sensitivity to light, hair loss, reddening of the cornea and skin rash and dermatitis.
Good sources of riboflavin include milk, yoghurt, cottage cheese, wholegrain breads and cereals, egg white, leafy green vegetables, meat, yeast, liver and kidney.
Vitamin B3 (Niacin)
Niacin (nicotinic acid and nicotinamide) functions as the co-substrate/co-enzyme for hydrogen transfer with numerous dehydrogenases. B3, is required by body to convert carbohydrates, fat into energy. It is essential for skin and nervous and digestive systems. It is involved in making hormones.
Unlike other B-group vitamins, niacin is very heat stable and little is lost in cooking.
Its deficiency causes Pellagra (chronic wasting disease;symptoms include dementia, diarrhea and dermatitis, irritability, loss of appetite, mental confusion, weakness and dizziness).
Good sources of niacin include meats, fish, poultry, milk, eggs, wholegrain breads and cereals, nuts, mushrooms and all protein-containing foods.
Vitamin B5 (pantothenic acid)
Pantothenic acid functions as the co-enzyme in fatty acid metabolism. It helps in breakdown of fats, protein and carbohydrate. It is also involved in formation of hormones and RBCs.
B5 is helpful in reducing stress.
Its deficiency causes fatigue, sleep disturbances, impaired coordination, loss of appetite, fatigue and insomnia, constipation, nausea and vomiting.
Each food item contain some amount of vitamin B5. Good sources of pantothenic acid include liver, meats, milk, beans, eggs, yeast, peanuts, whole grain and legumes.
Vitamin B6
Vitamin B6 (pyridoxine, pyridoxamine, and pyridoxal) functions as the co-enzyme in metabolism of amino acids and glycogen. It is involved in formation of protein and enzymes.
It influences brain processes and development, immune function and steroid hormone activity.
Its deficiency causes insomnia, depression, anemia, smooth tongue and cracked corners of the mouth, irritability, muscle twitching, convulsions, confusion, dermatitis and peripheral neuropathy (epileptiform convulsions in infants).
Good sources of pyridoxine include high protein food, cereal grains and legumes, green and leafy vegetables, fish and shellfish, meat and poultry, nuts, liver and fruit.
Vitamin B7 (biotin)
Biotin functions as the Co-enzyme in for energy metabolism, fat synthesis, amino acid metabolism and glycogen synthesis.
But High biotin intake can raise blood cholesterol levels.
Its deficiency causes conjunctivitis, central nervous system abnormalities such as hypotonia, lethargy, and pains, pale or grey skin, cracked sore tongue, depression, hallucinations, abnormal heart actions, loss of appetite, nausea, dry skin and scaly dermatitis, hair loss, alopecia, muscle pain, and weakness and fatigue.
Good sources of biotin include cauliflower, egg yolks, peanuts, liver, chicken, yeast and mushrooms.
Vitamin B9 (folate)
Folate or folic acid is required for formation of RBCs and development of fetal nervous system, DNA synthesis and cell growth. Folate is required for cell growth and division. It is required for better health of heart.
Intake of folic acid before and in early pregnancy, reduces the risk of spina bifida in the baby. Folic acid is the synthetic form of folate and is used extensively in dietary supplements and food fortification.
Its deficiency causes weight loss, tiredness, fatigue and weakness, folate-deficiency anemia (megaloblastic anemia) and (during pregnancy) an increased risk of a neural tube defects such as spina bifida for the baby.
Good sources of folate include green leafy vegetables, legumes, seeds, liver, poultry, eggs, cereals and citrus fruits.
Vitamin B12 (Cobalamine)
Vitamin B12 helps to produce and maintain the myelin surrounding nerve cells, mental ability, red blood cell formation and the breaking down of some fatty acids and amino acids to produce energy.
It converts carbohydrate, fat and proteins into energy. Vitamin B12 and folate, depend on the each other to work properly.
Its deficiency causes tiredness and fatigue, lack of appetite, weight loss, heart palpitations, shortness of breath, vision loss, smooth tongue and mental problems, such as depression and memory loss.
Good sources of B12 include liver, meat, milk, cheese and eggs, and non-vegetarian food items.
Foods that reduce absorption of B complex
Consumption of certain food items reduces the absorption of B vitamins. Some of them are listed below:-
- Medicines (antibiotics, aspirin, laxative, diuretics)
- Oral contraceptive pills
- Sleeping drugs
- Excessive sugar intake
- Alcohol, Coffee
Processing of foods, exposure to heat, milling of grains and prolonged storage also destroys or depletes amount of B vitamins present in food item.
B-complex is combination of 8 water soluble vitamins. The deficiency of these vitamins in body is responsible for slower metabolism, poor skin health, affected RBCs formation and other health risks. Researchers have found, B-complex is also beneficial in treating the symptoms of stress and anxiety. They also show beneficial effect in dermatitis, general tiredness and lethargy. Lack of these vitamins causes poor health of skin and hair. Vitamin B is easily destroyed by cooking and processing. These are not stored in body. One should take balance diet to prevent deficiency of these vitamins.
![]()
Hafizmuar at en.wikipedia[CC BY-SA 3.0 or GFDL] from Wikimedia Commons
"Starr 060916-8882 Thevetia peruviana" by Forest & Kim Starr. Licensed under CC BY 3.0 via Wikimedia Commons
By Manoj K (Own work) [CC BY-SA 3.0 via Wikimedia Commons 
By Victor Korniyenko (Own work) [CC BY-SA 3.0or GFDL] via Wikimedia Commons 
"Althea officinalis flor". Licensed under CC BY-SA 3.0 via Commons