Vitamins A and D

How it works

Vitamin A supports vision, epithelial integrity and immune function, while vitamin D promotes intestinal calcium and phosphate absorption to maintain bone mineralisation.

Prescribing in practice

• Avoid excessive intake, as both vitamins accumulate and chronic over-supplementation can cause hypervitaminosis A (including teratogenicity in pregnancy) and vitamin D toxicity with hypercalcaemia.
• Account for vitamin A and D already present in fortified formula or other supplements to avoid cumulative excess.
• Follow current prescribing references and a children's formulary for age-appropriate paediatric supplementation.

Monitoring

Routine biochemical monitoring is not generally required at supplementation doses, but review growth and clinical status and check calcium if toxicity is suspected.

Counselling the patient

• Give the daily supplement as directed and do not exceed the recommended amount.
• Pregnant women should avoid high-dose vitamin A supplements.
• Keep out of reach of children to prevent accidental overdose.

Evidence & guidelines

UK Healthy Start guidance recommends routine vitamin A, C and D supplementation for infants and young children to prevent deficiency.