Login
Search

Search
Search

Vitamin D Deficiency

NICE CKS Vitamin D deficiency in adults. Last revised Jan 2022 NICE Public Health Guideline [PH56] Vitamin D: supplement use in specific population groups. Last updated Aug 2017

Background Information

Vitamin D: fat-soluble vitamin that acts primarily to increase calcium and phosphorus absorption from teh bowel.

Acitve form: 1,25-dihydroxyvitamin D

In the UK, 80-90% of vitamin D is derived from skin exposure to sunlight, 10-20% derived from diet. 

Causes of vitamin D deficiency
  • Inadequate sun (UVB) exposure 
  • Intestinal malabsorption (e.g. Coeliac disease, Crohn's disease, cystic fibrosis) 
  • Severe liver failure 
  • End-stage chronic kidney disease
  • Hereditary vitamin D-deficiency rickets
  • Drugs (orlistat, antiepileptic drugs, etc.)

Risk factors
  • ≥65 y/o 
  • Low / no exposure to sun
  • Darker skin pigmentation
  • Pregnant / breastfeeding 
  • Obese (BMI >30)

Guidelines - Investigation and Diagnosis

Do not routinely test for vitamin D deficiency in asymptoamtic patients.
  • Asymptomatic patient at higher risk of vitamin D deficiency does NOT need testing 
  • Patients being treated with antiresorptive agent and vitamin D supplements does NOT need testing

Test of choice: serum 25-hydroxyvitamin D

Indications for checking vitamin D level:
  • Symptomatic
  • Suspected bone disease that may improve with vitamin D treatment
  • Bone disease that requires vitamin D deficiency correction prior treatment

Guidelines - Management and Prevention

Lifestyle advice:
  • Safe sunlight exposure 
  • Dietary advice on vitamin D and calcium intake 

Oral vitamin D3 treatment:
  • For rapid correction → loading dose (total of 300,000 IU over 6-10 weeks) followed by maintenance therapy (800-2,000 IU daily)
  • For non-urgent correction → maintenance therapy (800-2,000 IU daily)

Assess need for calcium supplementation:
  • If there is dietary insufficiency → advice to increase dietary calcium take 
  • If diet change not appropriate → calcium supplementation

NICE CKS states to seek specialist advice / arrange referral before starting vitamin D treatment in the following conditions.
 

Note: combination calcium and vitamin D preparations (such as Calcichew D3®) are not recommended for people needing high-dose vitamin D treatment, as they contain very low levels of vitamin D (200–400 IU per tablet) and may increase the risk of hypercalcaemia.

Lifestyle advice:
  • Safe sunlight exposure 
  • Dietary advice on vitamin D and calcium intake 

Consider vitamin D supplement 400 IU daily in:
  • ≥65 y/o with risk factors for vitamin D deficiency 
  • All other adults, particularly in autumn and winter

References


Author: Adams Lau
Reviewer: 
Last Edited: 22/02/25