Vitamin D Deficiency in Children

🧭 When to suspect

Vitamin D is essential for calcium and phosphate homeostasis and for the mineralisation of growing bone. In the UK there is no useful UVB sunlight between October and March, so deficiency is common – and it is largely preventable. Most affected children are entirely asymptomatic; when symptoms do occur they are non-specific (tiredness, diffuse bone or limb pain, proximal muscle weakness). The skeletal extreme is rickets; the dangerous, easily-missed acute extreme is symptomatic hypocalcaemia in infancy.

The defining primary-care skill is to prevent first and test selectively: supplement every at-risk child, confirm deficiency biochemically only where it is clinically indicated, and recognise the small number who need urgent or specialist care.

Raise suspicion in children with darker skin (African, African-Caribbean or South Asian family origin), limited sun exposure (concealing dress, housebound, routine sunscreen), prolonged or exclusive breastfeeding without supplementation, a vegan, vegetarian or restricted/faddy diet, malabsorption (coeliac, IBD, cystic fibrosis), obesity, chronic renal or liver disease, or use of enzyme-inducing medication (e.g. antiepileptics).

Source: NICE · SACN