They are natural components of food, usually present in small amounts. Unfortunately, our bodies can't produce them, so it's essential we get them through our diets. Deficiencies of any vitamin can lead to a specific health problems.
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Different Kinds Of Vitamins
Vitamins can be divided into 2 groups:
- Water-soluble (B vitamins and vitamin C)
- Fat-soluble (vitamins A, D, E, K)
B vitamins are further divided into:
- B1 (thiamine)
- B2 (riboflavin)
- B3 (niacin)
- B5 (pantothenic acid)
- B6 (pyridoxine)
- B7 (biotin)
- B9 (folate)
- B12 (cobalamin)
Water-soluble vitamins are released into the blood after absorption from food and they circulate freely among bodily fluids before being used in cells in the body. Excess amount of water-soluble vitamins are removed by the kidneys.
The body flushes these vitamins out fairly rapidly so they should ideally be topped up every day.
Fat-soluble vitamins are released into the lymphatic system after absorption and they require a protein carrier in order to be transported through the body. They are stored in adipose tissues (fat) and the liver before being used for bodily functions.
Excess amounts of fat-soluble vitamins are accumulated in the body and not released so they do not need to be topped up with the same frequency as water-soluble vitamins. Alternatively, there is a greater risk of toxicity from fat-soluble vitamins than from water-soluble vitamins.
Vitamin Sources, Functions and Deficiencies
|A||Eggs, meat, dairy, orange vegetables, apricots||Vision, growth and development, immune functions, reproduction||Night blindness|
|B1 (thiamine)||Whole grains, yeast, liver, fish, lean meat, milk||Cardiovascular and nervous system||Beriberi|
|B2 (riboflavin)||Dark green leafy vegetables, meats and dairy||Growth and tissue repair||Photophobia|
|B3 (niacin)||Lean meat, poultry, fish, peanuts, nuts, yeasts||Digestion, nervous system, skin||Pellagra|
|B5 (pantothenic acid)||Meat, mushrooms, avocados, egg yolk, yeast, sweet potato, broccoli||Growth and production of steroid hormones||Fatigue, insomnia, depression|
|B6 (pyridoxine)||Meat, whole grains, vegetables, nuts, beans, legumes||Healthy brain function, immune system||Dermatologic and neurologic changes|
|B7 (biotin)||Nuts, soy, eggs, milk and dairy, sweet potato||Immune system, hair and nail growth||Dermatitis, glossitis|
|B9 (folate)||Beans, legumes, citruses, whole grains, dark green leafy vegetables, poultry, pork, shellfish||Production of red blood cells, DNA synthesis||Birth defects in pregnant women, cardiovascular problems|
|B12 (cobalamin)||Shellfish, meat, poultry, milk and dairy, eggs (only animal sources)||Maintenance of the central nervous system||Impaired cell division, folate deficiency|
|C||Citruses, green peppers, sweet and white potatoes, tomatoes, berries||Immune system, wound healing, iron absorption||Scurvy|
|D||Fish liver oils, egg yolks, sunshine||Maintenance of calcium and phosphorus homeostasis||Rickets, osteomalacia, osteoporosis|
|E||Seeds, nuts, vegetable oils, olives, wheat germ, dark green leafy vegetables||Antioxidant, cell signaling and gene expression||Neuromuscular, vascular and reproductive system malformations|
|K||Dark green leafy vegetables, cauliflower, whole grains||Blood clotting, bone mineralization||Hemorrhage, anemia, prolonged clotting time|
Vitamins in Children's Diets
During the first 6 months of age, breastmilk/formula satisfies all vitamin needs (mostly, we'll come back to that). But as your child gets older and begins to eat more solids their requirements increase and it becomes more and more important to meet them with the food they eat.
The only exceptions are vitamins D and K. Vitamin K should be given within the first few days of life in order to prevent hemorrhagic disease – this is normally in the form of an injection right after birth. Vitamin D should be given as a supplement throughout the first year of life since nutrition (even breastmilk) is highly unlikely to be sufficient – formula is likely to contain added vitamin D though. In any case you should speak to your pediatrician about any supplements early in your child's life.
|0-6 months||7-12 months||1-3 years||4-8 years||9-13 years (boys)||9-13 years (girls)||14-18 years (boys)||14-18 years (girls)|
|B1 (thiamine) (mg)||0.2||0.3||0.5||0.6||0.9||0.9||1.2||1.0|
|B2 (riboflavin) (mg)||0.3||0.4||0.5||0.6||0.9||0.9||1.3||1.0|
|B3 (niacin) (mg)||2||4||6||8||12||12||16||14|
|B5 (pantothenic acid) (mg)||1.7||1.8||2||3||4||4||5||5|
|B6 (pyridoxine) (mg)||0.1||0.3||0.5||0.6||1.0||1.0||1.3||1.2|
|B7 (biotin) (mcg)||5||6||8||12||20||20||25||25|
|B9 (folate) (mcg)||65||80||150||200||300||300||400||400|
|B12 (cobalamin) (mcg)||0.4||0.5||0.9||1.2||1.8||1.8||2.4||2.4|
- Gallagher ML. The Nutrients and Their Metabolism. In: Mahan LK, Escott-Stump, S. Krause’s Food & Nutrition Therapy. International Edition, 12e. 2008. pg. 39-143.
- Basics in Clinical Nutrition, ed. Sobotka L (2004) Prague: Galen and ESPEN.
- Braegger C, Campoy C, Colomb V, Decsi T, Domellof M, Fewtrell M, Hojsak I, Mihatsch W, Molgaard C, Shamir R, Turck D, van Goudoever J. (2013) Vitamin D in the healthy European paediatric population. J Pediatr Gastroenterol Nutr. 56(6):692-701.
- Mihatsch W, Braegger C, Bronsky J, Campoy C, Domellof M, Fewtrell M, Mis NF, Hojsak I, Hulst J, Indrio F, Lapillonne A, Mlgaard C, Embleton N, van Goudoever J. (2016) Prevention of Vitamin K Deficiency Bleeding In Newborn Infants: A Position Paper by the ESPGHAN Committee on Nutrition. J Pediatr Gastroenterol Nutr. 63(1):123-129.
- Institute of Medicine, Food and Nutrition Board (1997) Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D, and fluoride. Washington, DC. National Academies Press.
- Institute of Medicine, Food and Nutrition Board (2001) Dietary reference intakes for vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. Washington, DC. National Academies Press.
- Institute of Medicine, Food and Nutrition Board (2000a) Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. Washington, DC. National Academies Press.
- Institute of Medicine, Food and Nutrition Board (2000b) Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. Washington, DC. National Academies Press.