Vitamins are substances that contain oxygen, carbon and hydrogen. Vitamins exist naturally in all living beings, both plants and animals.
Vitamins regulate a variety of the functions in our body and are essential for building tissues, assist in metabolizing proteins, carbohydrates and fats so that energy can be extracted from food. Vitamins also promote healing and prevent nutritional deficiency diseases.
Our body needs at least 11 vitamins; vitamin A, vitamin D, vitamin E, vitamin K, vitamin C and the B vitamin family – thiamin (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), vitamin B6, folate and vitamin B12.
Vitamin A, vitamin D, vitamin E and vitamin K all dissolve in fat and all are stored in fatty tissues.
Vitamin A is the moisturizing nutrient that keeps our skin and mucous membranes (the tissue that lines the eyes, nose, mouth and throat) smooth and supple. Vitamin A is the vision vitamin and it promotes growth of healthy teeth and bones.
Sources of Vitamin A:
- Carotenoids. These are precursors that our body transforms into a retinol-like substance. There are more than 500 carotenoids.
- Retinoids. Compounds found in foods of animal origin, such as liver, eggs, whole milk and butter. Retinoids provide preformed vitamin A, i.e. a nutrient our body can use without processing.
Vitamin D is the bone vitamin.
Vitamin D comes in three forms:
- Cholecalciferol is created when sunlight hits our skin and ultraviolet rays react with steroid chemicals in body fat just beneath the skin.
- Calciferol occurs naturally in egg yolk and fish oils.
- Ergocalciferol is synthesized in plants exposed to sunlight.
Vitamin E maintains a healthy reproductive system, muscles and nerves. Our body gets vitamin E from tocotrienols and tocopherols, two families of naturally occurring chemicals in vegetable oils, whole grains, nuts, and green leafy vegetables. Tocopherols, the more important source, have two significant characteristics: they are anticoagulants and antioxidants that reduce the blood’s ability to clot, thus reducing the risk of clot-related stroke and heart attack.
Vitamin K is a group of chemicals that our body uses to make specialized proteins found in blood plasma, the clear ﬂuid in blood. One such protein is prothrombin, the protein chiefly responsible for blood clotting. We also need vitamin K to make kidney and bone tissues. Like vitamin D, vitamin K is essential for healthy bones, activating at least three different proteins that take part in forming new bone cells.
Vitamin K is found in dark green leafy vegetables (broccoli, cabbage, spinach, kale, lettuce and turnip greens), liver, cheese, cereals, and fruits. However, most of what is needed comes from resident colonies of friendly bacteria in our intestines, an assembly line that churns out the vitamin day and night.
Vitamin C is essential for the development and maintenance of connective tissue (the muscle, fat and bone framework of the our body). Vitamin C speeds the production of new cells in wound healing, helps ﬁght off infection, protects our immune system, reduces the severity of allergic reactions and plays a role in the syntheses of hormones and other body chemicals.
Thiamin, Vitamin B1
Thiamin helps ensure a healthy appetite. It acts as a co-enzyme, a substance that works along with other enzymes, essential to at least four different processes by which our body extracts energy from carbohydrates. This vitamin is found in every body tissue, with the highest concentrations in the liver, heart, and kidneys.
The richest dietary sources of thiamin are unrefined cereals and grains, beans, lean pork, nuts, and seeds.
Riboflavin, Vitamin B2
Like thiamin, riboflavin is a co-enzyme. Without it, our body would not be able to digest and use carbohydrates and proteins. Like vitamin A, it protects the health of mucous membranes – the moist tissues that line the eyes, nose, mouth and throat.
We get riboflavin from foods of animal origin (fish, meat, poultry, eggs, and milk), whole or enriched grain products, and dark green vegetables, such as spinach and broccoli.
Niacin is one name for a pair of naturally occurring nutrients, nicotinamide and nicotinic acid. Niacin is essential for proper growth and like other B vitamins, it is intimately involved in enzyme reactions. Niacin is an integral part of an enzyme that enables oxygen to flow into body tissues. Like thiamin, it contributes to a healthy appetite and participates in the metabolism of fats and sugars.
Niacin is available either as a preformed nutrient or via the conversion of the amino acid tryptophan. Preformed niacin comes from meat; tryptophan comes from milk and dairy foods.
Vitamin B6 is a multiple compound, comprising three related chemicals: pyridoxal, pyridoxine and pyridoxamine. Vitamin B6 is a component of enzymes that metabolizes fats and proteins, and is essential for getting energy and nutrients from food.
The best food sources of vitamin B6 are liver, fish, chicken, lamb, pork, milk, eggs, unmilled rice (rice with the bran intact), whole grains, soybeans, potatoes, beans, seeds, nuts, and dark green vegetables, such as turnip greens.
Folate, also known as folic acid or folacin, plays a role in the synthesis of DNA, the metabolism of proteins, and the subsequent synthesis of amino acids used to produce new body cells and tissues. It is vital for normal growth and wound healing.
Beans, dark green leafy vegetables, liver, yeast, and various fruits are excellent food sources of folate.
Vitamin B12 is a unique nutrient in the sense that it is the only vitamin that contains a mineral, namely cobalt. Vitamin B12 makes healthy red blood cells. It protects myelin, the fatty material that covers our nerves and enables the transmission of electrical impulses, the messages, between nerve cells.
Vitamin B12 is made by beneficial bacteria living in the small intestine. Meat, poultry, fish, milk products, and eggs are good sources of vitamin B12.
Biotin is a component of enzymes that ferry oxygen and carbon atoms between cells. Biotin helps to metabolize fats and carbohydrates and is essential for synthesizing amino acids and fatty acids needed for healthy growth.
The best food sources of biotin are liver, egg yolk, nuts, and beans. If our diet do not provide all the biotin needed, bacteria in the gut will synthesize enough to makeup the difference.
Pantothenic acid is vital to enzyme reactions that enable the use of carbohydrates and create steroid biochemicals such as hormones. Pantothenic acid also helps stabilize blood sugar levels, defends against infection, and protects hemoglobin, the protein in red blood cells that carries oxygen through the body, as well as brain, nerve and muscle tissue.
Sources are meat, poultry, fish, beans, whole grain cereals.
How much of the vitamins is needed to stay healthy? Click here to find out.