Nutrients – Requirement And Sources
Some important nutrients (vitamins & minerals) required for human body along with their sources and usefulness is described below:
- Vitamin A
Function: Helps form and maintain healthy teeth, skeleton and soft tissue, mucus membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye. It promotes good vision, especially in low light.
Effect of Deficiency: One may notice difficulty seeing in dim light and rough/dry skin.
Sources: Carrots, sweet potato, pumpkin, green leafy vegetables, squash, cantaloupe, bell pepper, Chinese cabbage, beef, eggs, peaches.
- Vitamin B12
Function: Helps to make red blood cells, which carry oxygen around the body and helps the nervous system function normally. It also helps to reduce tiredness.
Effect of Deficiency: Symptoms include pernicious anemia, neurological problems and sprue.
Sources: Fortified cereals, liver, milk, cheese, trout, salmon, tuna, haddock, and egg.
- Vitamin C
Function: Helps to protect cells from damage. Helps with the formation of collagen, which is important for normal bones, gums, teeth and skin.
Effect of Deficiency: Symptoms include bruising, gum infections, lethargy, dental cavities, tissue swelling, dry hair and skin, bleeding gums, dry eyes, hair loss, joint paint, pitting edema, anemia, delayed wound healing, and bone fragility. Long-term deficiency results in scurvy.
Sources: Guava, bell pepper, kiwi, orange, grapefruit, strawberries, Brussels sprouts, cantaloupe, papaya, broccoli, sweet potato, pineapple, cauliflower, kale, lemon juice, parsley.
- Vitamin D
Function: Helps the body to absorb calcium and helps to keep bones strong. It also helps muscles to function normally.
Effect of Deficiency: In children a vitamin D deficiency can result in rickets, deformed bones, retarded growth, and soft teeth. In adults a vitamin D deficiency can result in osteomalacia, softened bones, spontaneous fractures, and tooth decay.
Sources: Sunlight, fortified foods, mushrooms, salmon, mackerel, sardines, tuna, eggs
- Vitamin E
Function: Helps to protect the cells in our bodies against damage.
Effect of Deficiency: Only noticed in those with severe malnutrition. However, suboptimal intake of vitamin E is relatively common.
Sources: Green leafy vegetables, almonds, sunflower seeds, olives, blueberries, most nuts, most seeds, tomatoes, avocado.
Function: Iron is an essential element for the formation of hemoglobin in red blood cells and plays an important role in transport of oxygen to body’s tissues. It also helps the brain to function normally.
Effect of Deficiency: Anemia with small and pale red blood cells. In children it is associated with behavioral abnormalities.
Sources: Almonds, apricots, baked beans, dates, lima beans, kidney beans, raisins, brown rice, green leafy vegetables, broccoli, pumpkin seeds, tuna, flounder, chicken meat, pork.
Function: Helps to build and maintain strong bones and teeth, as well as the normal functioning of nerves and muscles. It also helps blood clot normally.
Effect of Deficiency: Long-term inadequate intake can result in low bone mineral density, rickets, osteomalacia and osteoporosis.
Sources: Green leafy vegetables, legumes, tofu, molasses, sardines, okra, perch, trout, Chinese cabbage, rhubarb, sesame seeds.
Function: Helps to build strong bones and teeth and helps to release energy from food.
Effect of Deficiency: Very rare. Those at risk include premature infants, those who use antacids, alcoholics, uncontrolled diabetes mellitus and refeeding syndrome.
Sources: Legumes, nuts, seeds, whole grains, eggs, fish, buckwheat, seafood, corn, wild rice.
Function: Helps regulate the water content in the body and maintain a normal blood pressure. It also helps the nerves and muscles function normally.
Effect of Deficiency: Not a result of insufficient dietary intake. Caused by protein wasting conditions. Diuretics can also cause excessive loss of potassium in the urine. Low blood potassium can result in cardiac arrest.
Sources: Sweet potato, tomato, green leafy vegetables, carrots, prunes, beans, molasses, squash, fish, bananas, peaches, apricots, melon, potatoes, dates, raisins, mushrooms.
Function: Helps to release energy from food. It also helps to maintain strong bones and helps muscles and nerves to function normally.
Effect of Deficiency: Very rare due to abundance of magnesium in foods. Those with gastrointestinal disorders, kidney disorders, and alcoholism are at risk.
Sources: Legumes, nuts, seeds, whole grains, fruits, avocado.
Function: Helps regulate the water content in the body.
Effect of Deficiency: Does not result from low dietary intake. Low blood sodium typically results from increased fluid retention. One may notice nausea, vomiting, headache, cramps, fatigue, and disorientation.
Sources: Very small amounts found naturally in foods. Often added as salt (sodium chloride) during processing, preparation, preservation and serving. Currently intakes of sodium are too high and most people need to reduce their intake substantially.