| Types of Vitamins | Sources | Functions | Effect of deficiency |
| B1 (thiamine) | Milk, legumens, wheatgerm, yeast extract, nuts, whole grains | - Precursor of a coenzyme - Coenzyme for carbohydrates metabolisme |
- Beri-beri (muscle weakness, nerve disorder) - Fatigue |
| B2 (riboflavin) | Milk, wheatgerm, liver, eggs | - Component of coenzyme - Healthy nervous system |
- Sore eyes
- Skin lesions at the corner of mouth, nose and ears - Inflammation of tongue and lips |
| B3 (niacin) | Liver, rice, legumes, fish, yeast extract | - Component of coenzyme - Healthy nervous system, skin and intestines | - Pellagra (skin and gastrointestinal lesions) |
| B5 (pantothenic acid) | Fish, egg yolk, liver, meat | - Component of coenzyme for carbohydrates, protein and fatty acids metabolism | - Muscle cramps
- Fatigue - Grey hair - Low immunity |
| B6 (pyridoxine) | Fish, liver, milk, potatoes | - Coenzyme in amino acid metabolism - For red blood cell formation | - Kidney stone
- Muscular twitching - Diarrhea |
| B9 (folic acid) | Green vegetables | - For DNA and RNA
- For red blood cells formation - Regulating the function of iron |
- Miscarriage birth
- Cleft lips - Limb defects of babies |
| B12 (cobalamin) | Cheese, milk, egg, meat | - Coenzyme in nucleic acid metabolism - For red blood cells formation |
- Pernicious anaemia - Neurological disorders |
| H (biotin) | Legumes, vegetables | - Coenzyme in the synthesis of fat, glycogen and amino acid | - Nausea
- Fatigue - Muscular pains |
| C (ascorbic acid) | Orange, tomatoes, broccoli, cauliflower | - Fats and protein metabolism - Energy production |
- Scurvy (bleeding gums and bruised skin) |
- It is a group of complex organic compounds that are needed in small quantities by living organisms because vitamins can be reused in body metabolisms.
- Vitamins do not provide energy to body metabolism and vitamins are non-protein organic compounds.
- Living organisms cannot synthesise vitamins.
- Vitamins can be only obtained from diet.
- It is essential to maintenance of good health, normal growth and efficient metabolism.
- There are two categories in vitamins: fat-soluble vitamins and water-soluble vitamins.
| Types of Vitamins | Sources | Functions | Effect of deficiency |
| A (retinol) | Milk, carrots, tomatoes, eggs, fish oil, green vegetables, butter | - Builds visual pigments on retina for night vision
- Immunity - Growth of epithelial cells - Antioxidant - Build body resistance to diseases |
- Night blindness
- Xerophthalmia (cornea becomes dry) - Scaly skin |
| D (calciferol) | Formed (skin) during the presence of sunlight, fish liver oil, egg yolk, cheese | - Enhances absorption of calcium and phosphorus - Build strong bones and healthy teeth | - Rickets (weak bones) - Osteomalacia (softening of bones) |
| E (tocopherol) | Palm oil, cereals, nuts, green vegetables, olive oil, milk- | - Preserves healthy muscular system, blood circulatory (red blood cells) and nervous system
- Antioxidant - Maintain healthy function of the reproduction system |
- Premature aging
- Low fertility - Slow wound healing |
| K (phylloquinone) | Green vegetable, totatoes | - Helps in blood clotting | - Detective blood clotting - Anaemia |
