Vitamin D deficiency

Pre-referral guidelines for primary care providers

Vitamin D deficiency (25-OH vitamin D < 50 nmol/L) is common, with population estimates suggesting more than 20% of Victorians are deficient. Vitamin D is important in the regulation of bone and muscle strength as well as many other aspects of health. Vitamin D is derived largely from conversion in the skin from sunlight, rather than through the diet.

Most newborns have a vitamin D level of approximately 66% of maternal levels and there is very little vitamin D transferred to babies through breast milk.

For more information on vitamin D deficiency, please refer to the Royal Children’s Hospital clinical practice guidelines.

Diagnosis

  • The diagnosis is made by performing a serum 25-OH vitamin D level. This should be done in conjunction with an ALP, calcium and phosphate level. Vitamin D deficiency is classed as:
    • mild deficiency: 25-50nmol/L
    • moderate deficiency: 12.5-25nmol/L
    • severe deficiency: <12.5nmol/L
  • Consider screening vitamin D levels in those at risk:
    • Dark-skinned
    • Covered or veiled
    • Sedentary or predominantly indoors
    • Obesity
    • Renal/liver disease or malabsorption syndromes
    • Infant of a mother at risk of vitamin D deficiency.

Practice points

  • Vitamin D deficiency is common and screening (25-OH vitamin D, ALP, calcium, phosphate) should be considered in at risk individuals.
  • Consider administration of vitamin D supplementation (400-500 IU daily) to all at risk infants for 12 months.
  • Treatment of vitamin D deficiency can be undertaken using daily supplementation, high dose tablets (registered prescribers) or high dose liquids (hospital pharmacies or specific vitamin D clinics).
  • High dose supplementation (50,000-600,000 IU) has been shown to cause potential adverse effects when given to younger infants.
  • Consider referral of any children who have significant hypocalcaemia in the setting of vitamin D deficiency.

Management

For further dosing recommendations please refer to the Royal Children’s Hospital clinical practice guidelines.

  • Infants: consider administration of vitamin D supplementation (400-500 IU daily) to all at risk infants for 12 months using a suitable Over The Counter preparation:
    • Ostevit D liquid (0.1ml = 500 IU) or
    • Ostevit D Children’s Oral Drops (2 drops = 400 IU).
  • See handout (from BHS) regarding infant dosing of vitamin D.
  • Treatment of vitamin D deficiency can be undertaken using:
    • daily supplementation (1000-3000 IU, 1-3 tablets)
    • high dose tablets (registered prescribers, 50,000 IU, Cal D Forte or D-3-50)
    • high dose liquids (hospital pharmacies or specific vitamin D clinics, 100,000 IU/ml).
  • Avoid high dose vitamin D supplementation in those with significant hyperphosphataemia (to avoid nephrocalcinosis).
  • Avoid recurrent high dose supplements without monitoring vitamin D levels due to the risk of hypervitaminosis D (premature epiphyseal fusion, nephrocalcinosis).
  • Monitoring with annual or second yearly vitamin D levels in those with vitamin D deficiency.
  • Remember that high dose vitamin D will alter 25-OH vitamin D levels within 2 days of dosing, thus any levels performed at this time will tend to mislead.
  • Referral can be considered for children who:
    • have significant hypocalcaemia in the setting of vitamin D deficiency
    • require high dose vitamin D liquid ongoing

Referral pathways

  • Paediatric Immigrant Health Clinic
    • For families from immigrant backgrounds, referral to the Paediatric Immigrant Health Clinic at Lucas can be considered for ongoing high dose vitamin D.
      • Send referrals to: Dr David Tickell, Paediatric Immigrant Health Clinic, BCHC; fax 53380520
  • Other resources
    • Handout on vitamin D dosing for infants (from Ballarat Health Services)