Your body needs certain vitamins to remain healthy and function properly. Most people get enough vitamins from their diet, but some need supplementation. Fat-soluble vitamins, including vitamins A, D, E and K, are best absorbed when eaten with fats. B-complex vitamins and vitamin C readily dissolve in water, losing nutritional value when foods containing them are boiled, which can be reduced by cooking them briefly in little water. Various health issues arise with diets deficient in major vitamins.
Vitamin A
Vitamin A, or retinol, promotes healthy tissue linings in vision, respiratory, urinary and digestive systems. Vitamin A deficiency is rare in developed nations but causes blindness and susceptibility to infection in the developing world. In deficient individuals, the tissues in the airways become compromised and many die of lung infections or pneumonia. Also, excessive alcohol intake depletes vitamin A within the body.
B-Complex Vitamins
The B-complex vitamins consist of eight vitamins: thiamine, riboflavin, niacin, pantothenic acid, vitamin B6, biotin, vitamin B12 and folic acid. These vitamins process consumed food to create energy for the body and keep red blood cells healthy. Too little folic acid or vitamin B12 or B6 causes anemia and neurological damage. Folic acid is important in the development of the brain and spinal cord of a baby during pregnancy. Deficiencies in niacin, riboflavin or thiamine result in fatigue, digestive problems and skin conditions. Rarely occurring pantothenic acid or biotin deficiencies present as nervous system-related problems.
Vitamin C
Humans cannot synthesize vitamin C in the body, so it has to be consumed. It is an antioxidant involved in nerve impulses and protein metabolism. According to the Office of Dietary Supplements, infants, teenagers, and adults need more vitamin C than children, while smokers require 35 mg per day more than nonsmokers. Vitamin C deficiency causes scurvy, a disease whose signs include depression, fatigue, anemia and musculoskeletal disorders.
Vitamin D
Vitamin D is not common in foods. Most vitamin D comes from fortified foods such as milk and orange juice. It helps your body absorb calcium from your diet, which enables bone cells to grow efficiently. A deficiency in vitamin D causes fatigue, muscle pain and poor bone growth. In children, the deficiency is called rickets. In this disease, the bones grow slowly and become soft or malformed. In both adults and children with this deficiency, breakage of bones is common. The deficiency can be resolved by taking a vitamin D supplement or sitting in the sun 5 to 30 minutes per day during midday.
Vitamin E
Vitamin E has many forms within foods, but only alpha-tocopherol is recognized by the human body. The liver metabolizes vitamin E and the body uses it as an antioxidant to protect cells. Also, it is needed for a healthy immune system. Vitamin E deficiency is rare. People with disorders in digestive fat absorption may become deficient in this vitamin because it is fat soluble. Individuals affected by a deficiency have neurological problems, muscle weakness and an impaired immune system.
Vitamin K
The name "vitamin K" is taken from the German word for coagulation. Coagulation describes steps in blood clotting. Seven factors involved in clotting need vitamin K. People deficient in vitamin K have impaired blood clotting. Easy bruising, bloody stool or urine and nosebleeds are symptoms of this deficiency. Vitamin K is widespread in foods; therefore, deficiencies are uncommon. Vitamin K deficiency is most common in exclusively breast-fed infants.
References
- United States Food and Drug Administration: Fortify Your Knowledge About Vitamins
- National Institutes of Health Office of Dietary Supplements: Vitamin A and Carotenoids
- MedlinePlus: B Vitamins
- National Institutes of Health Office of Dietary Supplements: Vitamin C
- National Institutes of Health Office of Dietary Supplements: Vitamin D
- National Institutes of Health Office of Dietary Supplements: Vitamin E
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