They are one of the minor components of diet. They are vital in small amounts. They can be classified in two categories depending on their solubility.

  • Fat-soluble vitamins like vitamins A, D, E and K.
  • Water-soluble vitamins like vitamins B and C.

Water-soluble vitamin B complex plays a major role in depression. Subsequent table can help you in understanding the specific functions of these vitamins along with their common sources, recommended intake and deficiency symptoms.

Vitamin Functions D.R.I. Deficiency symptoms Sources
Thiamin (B1) Co-factors in decarboxylation 1.2mg/day Anorexia nervosa, Mentaldepression, nervousness, irritability, fatigue, peripheral neuropathy, poor memory, beriberi-dry and wet, digestive disturbances, muscular weakness, numb hands and feet. Whole grains, brown rice, seafood, beans, meats, liver, wheat germ and legumes.
Riboflavin (B2) Important part of flavoproteins 1.3mg/day Cracked skin and mucus membranes, eczema, photophobia, burning and itching of the eyes, neuropathy. Glandular meat like liver and kidney, hard cheese, milk and leafy green vegetables.
Niacin (B3) Forms nicotinic acid and nicotinamide 16mg/day Anorexia nervosa, muscular weakness, indigestion, skin eruptions,pellagra-symptoms are dementia, diarrhea, dermatitis (3D’s) Tuna fish, lean meats, whole grains, liver, eggs, avocados.
Pantothenic acid (B5) Constituent of CoA 5mg/day Depression, fatigue, alopecia, insomnia, weakness. Meat, whole grains, bran, molasses, nuts, chicken, eggs.
Pyridoxine (B6) Co-enzymes for various enzymes used in protein and neurotransmitters metabolism. 1.3-1.7 mg/day Irritability, nervous disorders, dizziness, learning disabilities. Liver, kidney (glandular meat) oatmeal, banana, cabbage, avocado, eggs.
Folate Work as enzyme co-substrate in the reactions of amino acid metabolism. 400mcg/day Anemia, mental depression, weakness, polyneuropathy, extreme fatigue, insomnia, irritability. Green leafy vegetables such as spinach, asparagus, broccoli, lean beef, potatoes, whole wheat bread, and dried legumes.
Cyano- cobalamin (B12) Co-enzyme in amino acid metabolism. 2.4mcg/day Pernicious anemia, mental deterioration, general weakness, trembling, menstrual problems, poor appetite, chronic fatigue. Liver and kidney, milk, eggs, fish, cheese.
Biotin Catalyses CO2fixation 30 mcg/day Fatigue, mental depression, eczema, insomnia, poor appetite. Milk, liver, egg yolk, fruits, unpolished rice