|Description||A fat-soluble vitamin.|
|Function/ Used for||Vitamin D helps the body to absorb and use calcium and phosphorus; which are essential for maintaining strong and healthy bones and teeth, as well as other body functions such as heart and muscle function.
Vitamin D is also important for blood clotting, the immune system and muscle growth, development and function.
EU NRV: 5µg (micrograms)
In July 2016 Public Health England published guidelines for vitamin D1:
· Babies from birth to 1 year: 8.5-10µg/day all year round.
· Children over 1 year and adults: 10 µg /day in the winter months
· Pregnant and breastfeeding women and population groups at risk of vitamin D deficiency (those with minimal exposure to sunshine and those from minority ethnic groups with dark skin): 10 µg /day all year round
Chief Medical Officer recommendations are that all children aged six months to five years should take a daily supplement containing vitamins A, C and D.
UK average daily intake
Requirements vary depending on age and gender. The UK National Diet and Nutrition Survey lists up-to-date intake requirements and average intakes2.
|As a supplement||Available as a single supplement. Also commonly available as part of a multivitamin and mineral formula.
Different multivitamin and minerals products will vary in the percentage NRVs they include. People should always check the label for information about a specific product.
In 2018 the UK food supplements industry agreed a voluntary safe upper level of vitamin D for food supplements of 75µg. Read statement
|Found in (dietary sources)||Good food sources include full-fat dairy products, oily fish, egg yolks and fortified margarine.
Food alone is unlikely to provide sufficient vitamin D.
Vitamin D is also formed by the action of sunlight on the skin (from May to September in the UK).
|Deficiency||Vitamin D deficiency results in poor growth, bone pain and deformities (rickets in children and osteomalacia in adults), osteoporosis, gum disease, constipation and muscle weakness.5|
|Precautions and contraindications||Vitamin D should be avoided in hypercalcaemia (high levels of calcium in the blood).
Safe Upper Level: there are differences of opinion.
In 2018 the UK food supplements industry set a voluntary safe upper level of 75µg for vitamin D in food supplements which allows for dietary intakes of up to 25µg without exceeding the most widely accepted safe upper level.
|Use in pregnancy and breastfeeding||There is no evidence of adverse effects in pregnancy at normal intakes.|
|Interactions e.g. with other medications||Anticonvulsants (used to prevent epileptic seizures) may reduce the effect of vitamin D by accelerating its metabolism.
The weight loss drug orlistat and cholesterol-lowering drugs can reduce the absorption of vitamin D and other fat-soluble vitamins (A, E and K).
Calcium may increase risk of hypercalcaemia.5,6
|Adverse effects||There is no risk of vitamin D toxicity from prolonged exposure to sunlight.
Excessive dietary intake may lead to hypercalcaemia, which can weaken the bones and damage the kidneys and heart.
3 Institutes of Medicine. Dietary reference Intakes for Calcium and Vitamin D. November 2010.
4 European Food Safety Authority. Scientific Opinion on the Tolerable Upper Intake Level of Vitamin D. June, 2012
5 Mason, P. Dietary Supplements. Pharmaceutical Press, London, 2001.
6 Gaby, A. R. A-Z Guide to Drug-Herb-Vitamin Interactions. HealthNotes 2006.