Vitamins are natural compounds that are required in small quantities, but cannot be produced by our own bodies. Vitamins are normally absorbed through our diet, but can also be taken as supplements. Vitamins have multiple biological functions, some vitamins act as hormones while others function as enzyme co-factors. Long before the discovery of vitamins, people knew that eating certain foods could prevent diseases. The chemical structure for most vitamins was not discovered until the early to mid 20th century. Vitamins can be either water soluble or fat soluble. Vitamins can be categorized as follows:
- B vitamins (B1, B2, B3, B5, B6, B7 and B9)
- Vitamin D
- Vitamin K
- Vitamin E
- Vitamin C
- Vitamin A
Vitamin A or retinol is fat soluble vitamin and has many biological functions. A deficiency in vitamin A can cause blindness (in extreme cases). The first signs of a vitamin A deficiency is night blindness (the inability to see in the dark). Vitamin A is present in butter fat, liver, dark leafy vegetables and dark colored fruits. Vitamin A also plays a role in maintaining healthy skin and a strong immune system. Vitamin A also acts as an antioxidant.
B vitamins is a family of water soluble vitamins that frequently act as co-factors of enzymes. Vitamin B1 (Thiamine) was the first discovered B vitamin and when deficient, causes the disease “beri-beri”. Beri-beri symptoms include extreme lethargy, fatigue, muscular and neurological symptoms. People of Asian countries are at risk for developing beri-beri when their diet consists mainly of white rice. Foods high in thiamine are meat, dairy, whole grains, rice bran and fruit.
Vitamin B6 is an important co-factor for the metabolism of amino acids. It is also important for many neurological functions as it is required for the synthesis of the neurotransmitters serotonin, adrenaline, nor-adrenaline and GABA. It is also needed for the release of glucose from glycogen. People deficient in vitamin B6 may develop sleep disturbances, skin problems and neuropathy.
Niacin (Vitamin B3) prevents the disease pellagra, which is often seen in communities that use un-processed corn as their main food supply. Processing corn with lime increases the bio-availability of niacin. Symptoms of pellagra include diarrhea, dermatitis, dementia, thickening of the skin, anxiety, depression and fatigue. Niacin is present in meat, liver, vegetables and fruits and mushrooms. Niacin can be synthesized from the amino acid tryptophan. Taking too much niacin (as a supplement) can cause flushing of the skin.
Vitamin C (ascorbic acid) is a water soluble vitamin present in high quantities in citrus fruits, tomatoes, potatoes and green peppers. Vitamin C is required for the formation of collagen. Vitamin C is an important nutrient for the proper functioning of our skin, mucous membranes and immune system. A vitamin C deficiency causes the disease scurvy, which symptoms include spongy bleeding gums and bleeding wounds on the body. Untreated scurvy is fatal.
Vitamin D is a group of fat soluble pro-hormones, vitamin D2 and vitamin D3 (cholecalciferol). Vitamin D plays a major role in bone formation and bone maintenance and is essential for a healthy immune system. Vitamin D is present in fish oils, fatty fish (such as salmon), liver, egg and beef. Vitamin d is also synthesized in our skin when exposed to UV-B sunlight.
Vitamin K deficiencies rarely occur as most people get enough vitamin K through their diet. Vitamin K is also produced by bacteria lining the gut. Vitamin K is a fat soluble vitamin that is required for blood coagulation. Vitamin K is found in leafy green vegetables such as spinach, kale, broccoli, brussels sprouts and avocados and kiwis. Vitamin K can be applied topically to reduce the bruising after cosmetic surgery and to repair broken blood vessels in the skin.
