Vitamin Supplement Pregnancy: A

Colecalciferol (Vitamin D3)

Brand names: Fultium-D3, Desunin, InVita D3, Thorens

Adult dose

Dose: 800–1000 units/day (maintenance); loading: 50,000 units weekly × 6–8 weeks if deficient (<25 nmol/L)

Route: oral

Frequency: daily (maintenance) or weekly (loading)

Max: 4000 units/day (NHS guidance); short-term loading: 50,000 units/week

Public Health England: 10 micrograms (400 units) daily throughout autumn/winter for general population; all care home residents year-round

Route: oral

Frequency: once daily

Max: 4000 units/day

Concentration: 400 units, 800 units, 1000 units tablets/capsules; drops (200 units/drop) units/day/ml

NICE: 400 units daily for all children; 1000 units/day if deficient; high-dose loading only under specialist guidance in children <12 years

Renal

If eGFR <30 ml/min: use activated form (alfacalcidol/calcitriol) — renal 1α-hydroxylation impaired

Hepatic

Use with caution — may need alfacalcidol if severe hepatic impairment (25-hydroxylation impaired)

PHE guidance 2016: all UK residents advised to take 400 units/day in autumn/winter
Care home residents and housebound patients: year-round supplementation recommended
Falls and fracture prevention: NICE NG187 recommends calcium + vitamin D for care home residents with osteoporosis risk

Reference: BNFc; BNF 86; NICE NG187; PHE vitamin D guidance 2016. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Pathways