Milk is a source of protein, vitamins B2 and B12 and the minerals calcium, phosphorus and potassium. Additionally, milk contains a mixture of nutrients that are important for various functions in the body.

A glass (150 ml) of milk contains a mixture of various nutrients.

  • Nutrients in milk5.1 g protein
  • 180 mg calcium (23% of the RNI)
  • 144 mg phosphorus (21% of the RNI)
  • 236 mg potassium (12% of the RNI)
  • 0.34 mg vitamin B2 (24% of the RNI)
  • 0.4 mcg vitamin B12 (16% of the RNI)


Milk has a protein content of about 3.5% of which 80% of the milk protein is casein and 20% whey protein. (1) Milk protein has a high protein quality as it contains all the essential amino acids in large amounts and is easily digestible (2). Protein helps to build and maintain muscle mass and also plays a role in the development of bones (3).

Vitamins B2 and B12

Milk also naturally contains vitamins B2 and B12 which contribute to the release of energy in the body (1). Vitamins B2 and B12 also help reduce fatigue and are important for the functioning of the nervous system. (4) Vitamin B12 is only found in animal products, such as milk and dairy, meat, fish and eggs. People who don’t eat any animal products (vegans), have undergone gastric sleeve surgery, suffer from gastrointestinal infections, have a reduced production of gastric acid or taking certain medications long term risk of a shortage of vitamin B12. (5).


Children need calcium for developing bones and teeth. For adults this mineral contributes to the maintenance of bone tissue (6). Calcium also supports muscle contraction and the conduction of nerve impulses in muscles, coagulation of blood and functioning of digestive enzymes. (7)


Just like calcium, phosphorus contributes to the maintenance of bones. As well as this, phosphorus plays a role in energy metabolism and the normal functioning of cell membranes in the body. (8)


Potassium contributes to the normal functioning of the nervous system and muscles. This mineral is also plays a role in maintaining a normal blood pressure. (9)

Read more:


  1. McCance and Widdowson 7th ed. Reference Nutrient Intakes (RNI) from Department of Health, Dietary Reference Values for Food Energy and Nutrients for the United Kingdom, HMSO, 1991
  2. Tomé, D. (2012). Criteria and markers for protein quality assessment – a review. British Journal of Nutrition, 2012; 108, S222–S229.
  3. EFSA 2010;8(10):1811 and 2011;9(6):2203
  4. EFSA 2010;8(10):1814
  5. Department of Health & Human Services (2017). Vitamin B12 Dietary Supplement Fact Sheet. Retrieved via in July 2017.
  6. EFSA 2009; 7(9):1210-1272 and EFSA 2010;8(10):1725 2011;9(6):2203
  7. EFSA 2009; 7(9):1210
  8. EFSA 2009; 7(9):1219
  9. EFSA2010; 8(2):1469