A Guide to Vitamins

Posted on June 21, 2013 by .

What are vitamins?

Vitamins are organic compounds that are necessary for normal growth and nutrition. However, since vitamins cannot be synthesised by the body, it must be obtained in limited amounts through your diet. The human body needs 13 essential vitamins to function, and each serves a purpose. Vitamins are classified into two types:

  • Water-soluble vitamins
    As the term suggests, these types of vitamins dissolve easily in water and are usually excreted from the body. There are nine water soluble vitamins: B1, B2, B3, B6, B12, C, biotin, folic acid, and pantothenic acid. Take note that vitamin B12 (Cobalamin) is the only water-soluble vitamin that can be stored in the liver for several years.

  • Fat-soluble vitamins
    These vitamins, on the other hand, are absorbed through the intestinal tract through lipids (i.e. fats). There are four fat-soluble vitamins: A, D, E, and K.  Since fat-soluble vitamins are more likely to accumulate in the body than water-soluble vitamins, they are more likely to result in hypervitaminosis.

Function and sources

Here are the functions and sources of each vitamin:

Vitamin A
This vitamin serves several functions, including the following: it helps maintain the immune system by protecting against infection; promote the growth of skin and cell health; reduce the risk of certain cancers; protect the heart and other cardiovascular conditions; and boost the development and function of vision.

Sources: Vitamin A is found naturally in foods such as liver, carrots, spinach, fortified milk and dairy products, fish, and beef.

Vitamin B1 or Thiamine
Otherwise known as thiamine, vitamin B1 helps body cells produce energy from carbohydrates. Deficiency in thiamine can lead to beriberi, wet brain, and optic neuropathy.

Sources: Thiamine can be found naturally in whole grains, banana, avocado, nuts, rice, pastas, breakfast cereals, egg, and legumes.

Vitamin B2 or Riboflavin
This vitamin is important in promoting body growth, and producing red blood cells and energy. Signs of riboflavin deficiency include red and cracked lips, cracks at the corner of the mouth, sore throat, mouth ulcers, eye disorders like cataracts, and dry and flaky skin.

Sources: You can get riboflavin naturally from sources such as green leafy vegetables, lean meats, eggs, dairy products, tomatoes, almonds, yeast, and mushrooms.

Vitamin B3 or Niacin
Niacin is a type of B vitamin that helps the body produce energy, use fatty acids and sugars, maintain the skin, and lower cholesterol. Signs of niacin deficiency include skin problems and diarrhoea.

Sources: While the body produces some niacin, you can get the vitamin in protein-rich foods such as peanut butter, legumes, avocado, eggs, potato, poultry, and legumes.

Vitamin B6 or Pyridoxine
Vitamin B6 helps the body produce proteins (which are needed for making body cells), haemoglobin (necessary for transporting oxygen in the blood), insulin (a hormone that regulates the quantity of glucose in the blood), and antibodies (a blood protein that fights infection).

Sources: Pyridoxine is found in foods such as pork, kidney, liver, whole grains, nuts, poultry, legumes, and dairy products.

Vitamin B12 or Cobalamin
B12 is one of the B vitamins. It helps the body produce red blood cells and maintain the central nervous system. Low levels of cobalamin can lead to anaemia, weakness, loss of balance, nerve damage, and numbing/tingling of extremities.

Sources: Vitamin B12 can be found naturally in animal-derived foods like poultry, eggs, milk, dairy products, fish, and shellfish.

Biotin
Biotin, also known as vitamin H, is needed for producing fatty acids and hormones, promoting cell growth, and breaking down carbohydrates and proteins in food. Lack of biotin is rare because intestinal bacteria produce more than what the body needs daily, although deficiencies do occur.

Sources: Foods rich in biotin include liver, green leafy vegetables, peanuts, Saskatoon berries, and peanuts.

Vitamin C
Also known as ascorbic acid, vitamin C is an antioxidant known for boosting the immune system and treating the common cold. It also helps absorb iron from food made of plant sources, form and repair tissues like bones and red blood cells, heals wounds, keeps gums healthy, and prevent infection.

Sources: The richest sources of vitamin C are fruits and vegetables, although it is also available in eggs, fish, and beef.

Vitamin D
This vitamin promotes the absorption of phosphorus and calcium, which are needed for the development of bones and teeth. It is also known as the "sunshine vitamin" since your body synthesises it after adequate exposure to sunlight (i.e. 10 to 15 minutes, three times per week).

Sources: So aside from adequate sunlight, vitamin D sources include eggs, cheese, salmon, fortified milk, breakfast cereals, sardines, and mackerel.

Vitamin E
Also known as tocopherol, vitamin E is an antioxidant that protects the body from certain illnesses like cancer and heart disease. Lack of vitamin E can cause myopathies (a muscular disease), retinopathy (eye disease that leads to vision impairment or loss), ataxia (loss of full control of body movements), and loss of immune response.

Sources: Vitamin E sources include margarine, dark green vegetables (e.g. asparagus, turnip, broccoli), sunflower oil, papaya, and wheat germ oil.

Folate or folic acid
Vitamin B9 and folate are some of the aliases for folic acid, a water-soluble vitamin needed for the production of DNA and RNA, which is needed for producing new body cells. Folate also works with vitamin B12 to create new red blood cells. Lack of folic acid in the body can lead to anaemia and impaired cell growth.

Sources: Folic acid sources include liver, legumes (e.g. asparagus and turnip greens), fortified cereals, green leafy vegetables, peanut butter, wheat germ, and egg yolk.

Vitamin K
This fat-soluble vitamin helps stop bleeding by helping blood to clot. It also promotes bone development and the healing of wounds. Without enough vitamin K, blood wouldn’t clot sufficiently.

Sources: You can get vitamin K from beef, turnip greens, liver, eggs, cereals, broccoli, asparagus, Brussels sprouts, kale, and spinach.

Pantothenic acid
Pantothenic acid is a type of vitamin B are essential for producing energy and breaking down fat, protein, and carbohydrates in food. It also helps in the production of hormones. Deficiency of pantothenic acid is rare, although it can occur. Symptoms are similar to vitamin B deficiencies, including low energy, numbness, restlessness, nausea, and muscle cramps.

Sources: Meat is a major source of pantothenic acid. So are avocados, broccoli, rice, whole-grain cereals, mushroom, and poultry.

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