Vitamins

• Micronutrients

  • Vitamins
  • Fat & Water Soluble
• Vitamins

  • Needed in smaller amounts - milligrams (mg) or micrograms (μg)
  • Most micronutrients are essential, which means they must be supplied through consumption as the body cannot synthesise them
  • Each vitamin has a specific function in the cells of the body
• Fat-soluble vitamins

  • The body stores fat-soluble vitamins in adipose tissue and the liver, and reserves of these vitamins can stay in the body for days and sometimes months
  • Dietary fats (triglycerides in lipoproteins) help the body absorb fat-soluble vitamins through the intestinal tract
  • Vitamins A, D, E, and K are fat-soluble
• Water-soluble vitamins


  • Water-soluble vitamins do not stay in the body for long and cannot be stored
  • They leave the body via the urine
  • Because of this, people need a more regular supply of water-soluble vitamins than fat-soluble ones
  • Vitamin C and all the B vitamins are water-soluble
• Vitamin Classification Overview

  • Fat Soluble Vitamins
  • Water Soluble Vitamins
• Fat Soluble Vitamins

  • Dissolve in fat/ oil therefore require transport in the bloodstream via triglycerides in lipoproteins
  • Stored in adipose tissue or liver
• Water Soluble Vitamins

  • Dissolve in water, therefore transported freely and easily in the blood
  • Body cannot store most of them, therefore excess lost in urine
• Vitamins B1 (Thiamin), B2 (Riboflavin) + B3 (Niacin) - B complex


  • They act as coenzymes in the metabolism (breakdown) of macronutrients and release their energy
  • They do not provide energy but bind to enzymes which activates them to metabolism macronutrients
  • B1 coenzyme for CHO
  • B2 coenzyme for CHO, lipids, protein
  • B3 coenzyme for catabolism + anabolism of CHO, lipids and fats
• Food sources for Vitamins B1 (Thiamin), B2 (Riboflavin) + B3 (Niacin) - B complex


  • Wholegrain or fortified bread and cereal products (B1,B2,B3)
  • Meat, poultry, legumes (B3)
  • Milk and milk products (B2)
  • Dark green leafy vegetables (such as broccoli, turnip greens, asparagus and spinach) (B3)
  • yeast and vegemite (B1,B2)
• Folic Acid


  Synthetic/ artificial form added into foods (or supplements), e.g. fortified breads
• Folate


  Naturally occurring form found in food
• Functions of Folate/Folic Acid B9


  • Acts as a coenzyme to assist with energy production and metabolises amino acids. Also acts as a coenzyme in the synthesis of DNA and cell replication
  • Development of red blood cells (RBC) - deficiency in folate results in immature & abnormally large RBCs that can't effectively transport oxygen through capillaries (megaloblastic anaemia)
  • Formation of neural tube - forms the early brain and spine. Inadequate amounts (deficiency) during early pregnancy can lead to spina bifida (a spinal cord defect) and anencephaly (a brain defect)
• Vitamin B12- Cobalamin


  • Chemical name: cobalamin (natural)
  • Synthetic counterpart: cyanocobalamin
• Functions of Vitamin B12

  • Acts as a coenzyme in DNA synthesis formation and in metabolism of protein to produce energy
  • Deficiency in B12 leads to anaemia - pernicious (low RBC count) and megaloblastic
  • B12 is needed to convert folate into its active form therefore deficiency can lead to megaloblastic
• Food sources of Vitamin B12

  • Meat
  • Milk and milk products
  • Eggs
  • Seafood
  • Fortified products (soy milks, cereals)
  • *vegan diets are at risk of low B12
• Vitamin C (Ascorbic Acid)


  • Highly susceptible to being destroyed e.g., heat
  • Synthesis of Collagen - collagen is the main component in connective tissue (e.g. tendons, ligaments, skin) and aids in wound healing as acting as glue (forming scars)
  • Acts as an antioxidant - it removes free radicals (unstable atom) caused by oxidative stress which damages cells and accelerates aging process
  • Assist with iron absorption - protects iron from free radicals
  • Scurvy is caused by a deficiency of vitamin C (hypovitaminosis)- symptoms include fatigue, inflammation of gums, broken capillaries (insufficient collagen synthesis)
• Sources of Vitamin C

  • Kiwifruits
  • Strawberries
  • Citrus fruits (oranges and limes)
  • Leafy vegetables (Brussel sprouts, spinach and broccoli)
  • Capsicum
• How to prevent Vitamin A deficiency

  • The best way to prevent vitamin A deficiency is to eat a healthy diet that includes foods that contain vitamin A. Vitamin A can be found naturally in:
  • Green vegetables, such as leafy greens and broccoli.
  • Orange and yellow vegetables, such as carrots, pumpkin, sweet potatoes and squash.
  • Orange and yellow fruits, such as oranges, mangos, cantaloupe and papayas.
  • Dairy products.
  • Liver, beef and chicken.
  • Certain types of fish, such as salmon.
  • Eggs.
  • Cereals, rice potatoes, wheat and soybeans fortified with vitamin A.
• Signs and symptoms of Vitamin A deficiency

  • One of the early signs of vitamin A deficiency is night blindness (nyctalopia). If you have night blindness, you have trouble seeing well in the dark, but you can see normally if enough light is present. A retinal disorder causes night blindness.
  • As the vitamin A deficiency worsens, the whites of your eyes and your corneas can become dry and you aren't able to produce tears (xerophthalmia). Foamy spots called Bitot spots may appear in the whites of your eyes. Open sores on your corneas (corneal ulcers) may appear, or drying or clouding of your corneas (keratomalacia), which can lead to blindness.
• Complications of Vitamin A deficiency

  • Eye problems: Vitamin A is a key factor in many functions of your eyes. Vision loss and blindness can occur.
  • Skin issues: A lack of vitamin A can cause dry, scaly and/or itchy skin.
  • Infertility: Vitamin A plays an important role in your reproductive system. Vitamin A deficiency can lead to trouble conceiving and infertility.
  • Growth issues: Vitamin A deficiency can cause delayed growth and development in children.
  • Respiratory tract infections: Vitamin A deficiency can cause problems with your immune system. This can lead to infections in your chest and throat.
• Vitamin D: Calciferol


  • Body can synthesise Vitamin D with the help of sunlight
  • best source of vitamin D is from its production in the skin from cholesterol. dependent on ultraviolet radiation (UV) from the Sun
  • Absorption of minerals - increasing blood concentrations of calcium and phosphate through enhancing absorption and reducing urine excretion
  • Deficiency of vitamin D - symptoms include muscle and joint weakness/pain but can lead to rickets (bones fail to develop properly) and osteomalacia (bones turn soft and brittle)
• Food sources of Vitamin D

  • Fortified margarines
  • Oily fish (salmon, mackerel, herring)
  • Liver
  • Eggs
• Vitamin E


  Vitamin E is the name given to a group of 8 vitamins. It is also known as tocopherol.
• Functions of Vitamin E


  • Vitamin E is as an antioxidant, like vitamin C
• Sources of Vitamin E

  • Plant seeds, especially sunflower seeds
  • almonds, hazelnuts,
  • vegetable oils (e.g., olive oil and canola oil)
  • Tomato, Avocado, spinach
• Vitamin K

  Comes in two forms: phylloquinone & menaquinone
• Functions of Vitamin K

  • Blood clotting - vitamin K is required for the synthesis of blood clotting proteins
• Sources of Vitamin K

  • Green leafy veg (kale, broccoli, spinach)
  • Cabbage and brussel sprouts
  • Menaquinone is produced from foods fermenting in large colon such as sauerkraut, natto and cheeses
• Fat Soluble Vitamins

  • Vitamin A- retinol and beta carotene
  • Dissolve in fat/ oil therefore require transport in the bloodstream via triglycerides in lipoproteins
  • Stored in adipose tissue or liver
  • Vitamin D- Cholecalciferol
  • Vitamin E- tocopherols
  • Vitamin K
• Water Soluble Vitamins

  • Vitamin B1- Thiamine
  • Vitamin B2 – Riboflavin
  • Vitamin B3 – Niacin
  • Vitamin B12 – Cobalamin
  • Vitamin B9 – Folate or folic acid
  • Vitamin C
  • Dissolve in water, therefore transported freely and easily in the blood. 
  • Body cannot store most of them, therefore excess lost in urine