Clinical Practice Guidelines : Vitamin D deficiency

Vitamin D deficiency

PIC Endorsed

Key points

Vitamin D is essential for bone and muscle health. Low vitamin D and low calcium and/or phosphate can cause nutritional rickets
Sunlight��is the most important source of vitamin D at all ages
Vitamin D deficiency is common in risk groups and should be self-managed wherever possible - through education, behaviour change and supplementation as required
In Australia, nutritional rickets is generally only seen in infants and children with dark skin

Background

Sunlight��(UVB) is the most important source of vitamin D (>90%) through skin synthesis of D3. This varies with

Skin colour: people with dark skin ( ��V and VI) require greater UVB exposure compared to people with light skin
Skin exposure: covering clothing may result in low vitamin D levels
Season/UVB availability: during winter there may not be enough UVB to maintain adequate vitamin D levels in southerly latitudes. Sunscreens do not result in low vitamin D with normal use

Only small amounts of vitamin D are available from diet:

the main natural food source is fish
breastmilk, despite its other benefits, contains almost no vitamin D
infant formula is fortified with vitamin D

In the absence of sun exposure,��recommended intakes of vitamin D��are:

0–12 months old: 400 units daily
1–18 years old: 400–600 units daily

25-OH-D is used to measure vitamin D status
The recommended 25-OH-D level is��≥50 nmol/L at all ages and during pregnancy

Definitions of vitamin D status
Severe deficiency	<12.5 nmol/L
Moderate deficiency	12.5–29 nmol/L
Mild deficiency	30–49 nmol/L
Sufficient	≥50 nmol/L
Elevated	≥250 nmol/L*

*Toxicity is defined as serum 25-OH-D >250 nmol/L with hypercalcaemia and suppression of parathyroid hormone (PTH)

Assessment

Risk factors

Lack of skin exposure to sun (time inside, covering clothes)
Dark skin
Medical conditions affecting Vitamin D metabolism (obesity, liver/renal failure, severe malabsorption, medications)

Infants: exclusive breastfeeding AND any of: the above risk factors, maternal deficiency or prematurity

History

Time outdoors��and covering clothing
Dietary history (calcium intake, breastfeeding/formula in infants)
Previous vitamin D levels and treatment

a wide range of formulations are available
check dosing (photoboard) and adherence

Family understanding
Non-specific bony/muscular pain, fatigue with exercise
Poor growth, motor delay and irritability (infants)
Symptoms of low calcium: muscle cramps, tetany, stridor, seizures (rare beyond 6–12 months of age)

Examination

Growth parameters, exclusion of other musculoskeletal pathology
Delayed dentition (no teeth by 9 months, no molars by 14 months)
Rickets:

long bone deformity (eg genu varum/valgus - if weight bearing)
widening of wrists/ankles
delayed anterior fontanelle closure (normally closed by 2 years)
frontal bossing
rosary (widening of ribs at costochondral junction)
increased risk of fracture

Management

Investigation and treatment of low vitamin D

�� vitamin_d_deficiency

Breast fed infants <12 months with other risk factors can usually start supplements (400 units daily) without investigations, provided they do not have symptoms/signs
Consider admission: symptomatic hypocalcaemia (including tetany, stridor, seizures) or severe rickets
Specialist review: infants with symptoms/signs, clinical rickets, abnormal serum calcium, or vitamin D deficiency not responding to high dose supplements

Investigations

Breastfed babies can usually be started on supplements without testing
Screen children/adolescents with one or more risk factors for low vitamin D (25-OH-D, Ca, PO₄, and ALP)
Also check PTH if low calcium intake, symptoms, or multiple risk factors
Infants and children with rickets need additional investigations:

��25-OH-D, Ca, PO₄, ALP, Mg, PTH, UEC, urine Ca, PO₄, creatinine; X-ray L wrist, clinical photos
X-ray changes of rickets - osteopenia, metaphyseal widening/splaying/fraying

Treatment

Children with low vitamin D should be treated (see table below) to restore their levels to the normal range (≥50 nmol/L)

There is limited evidence to support high dose treatment in infants <3 months

Ensure adequate calcium intake��(see calcium intake table below). Cheese, yoghurt and fortified soy dairy are useful sources of calcium in children who dislike cow milk. Consider supplements if poor intake
Education on sun protection and exposure��(see sun exposure table below).�� Children/young people with dark skin can tolerate intermittent sun exposure without sunscreen, although hats/sunglasses are still recommended
Children with nutritional rickets should be managed under specialist guidance. The minimum recommended dose of vitamin D is 2000 units daily for minimum of 3 months, together with oral calcium 500 mg daily (either via diet or supplements). Phosphate supplements may also be needed

Treatment of low vitamin D

Age	Level (deficiency)	Treatment Oral doses D3/colecalciferol 1 microgram = 40 units	Maintenance/prevention in children with ongoing risk factors
Preterm	Mild 30–49 nmol/L	200 units/kg/day, maximum 400 units/day	200 units/kg/day, maximum 400 units/day
Preterm	Moderate or severe <30 nmol/L	800 units/day, review after 1 month	200 units/kg/day, maximum 400 units/day
<3 months (term)	Mild 30–49 nmol/L	400 units/day for 3 months	�� 400 units daily
<3 months (term)	Moderate or severe <30 nmol/L	1,000 units/day daily for 3 months	�� 400 units daily
3–12 months	Mild 30–49 nmol/L	400 units/day for 3 months	�� 400 units daily
3–12 months	Moderate or severe <30 nmol/L	1,000 units/day for 3 months OR 50,000 units stat and review after 1 month (consider repeating dose)	�� 400 units daily
1–18 years	Mild deficiency 30–49 nmol/L	1,000-2,000 units/day for 3 months OR 150,000 units stat	400–600 units daily, OR 3000–4000 units once weekly, OR 150,000 units at start of Autumn
1–18 years	Moderate or severe <30 nmol/L	1,000–2,000 units daily for 6 months OR 3,000–4,000 units daily for 3 months OR 150,000 units stat and repeat at 6 weeks

Many hospital pharmacies compound 100,000 units/ml of colecalciferol (Vitamin D3) in oil
50,000 units tablets are available for authorised prescribers, community compounding pharmacies or via the Special Access Scheme
Most adult tablets are 1000 units, the strength of liquid formulations/drops varies widely

Calcium intake

Age	Adequate intake (AI)	Estimated average requirement (EAR)	Recommended dietary intake (RDI)
0–6 months	200 mg
7–12 months	270 mg
1–3 years		360 mg	500 mg
4–8 years		520 mg	700 mg
9–11 years		800 mg	1000 mg
12–18 years		1050 mg	1300 mg

See

��Ongoing monitoring and self-management

Breastfed infants at risk of low vitamin D should be given 400 units vitamin D daily for at least the first 12 months��

Supplementation is usually not required in fully formula fed infants

Follow up bloods (25-OH-D, Ca, PO₄, ALP, and PTH if previously elevated)

Not usually required in mild deficiency
Check at 1 month in infants, at 3 months if older

Children with risk factors for low vitamin D require ongoing monitoring and a plan to maintain vitamin D and calcium status with behavioural change and supplementation as required
Provide education and a plan for self-management: consider 400–600 units daily OR 3000–4000 units once weekly over the cooler months (May–August) to avoid need for blood testing and the need for high dose therapy��

Consider consultation with local paediatric team

All children with symptomatic hypocalcaemia or severe rickets (will require admission)
Children presenting with clinical rickets, abnormal serum calcium, or vitamin D deficiency not responding to high dose supplements (require specialist consultation and should be referred to endocrinology)

Consider transfer when

Care required is beyond the comfort level of the local hospital

Parent information

Additional notes

Vitamin D medications
There are a number of Vitamin D preparations on the market
Some preparations are highly concentrated (up to 1000 units per drop) and overdose is possible
Check which supplement the family are taking

High dose therapy

Many local community health centres have high-dose prescribers
Medical practitioners can obtain Therapeutic Good Administration authorisation to treat patients with high dose Vitamin D (usually 50,000 units D3 capsules)

Sun exposure

Skin colour		Light to olive skin type I-IV	Naturally dark skin type V-VI
�� �� �� Infants, children, adolescents	�� Summer or UV index >= 3	Avoid sunburn, full sun protection with sunscreen/hat/clothing/shade and sunglasses recommended	Avoid sunburn, able to tolerate intermittent sun exposure without sunscreen, hat and sunglasses still recommended
		Encourage active outside play or physical activity during and after school/preschool
	�� �� Winter	Sun protection recommendations vary with latitude/UV index. If UV index <3, sun protection not required unless in alpine regions, outside for extended periods or near highly reflective surfaces such as snow/water	Sunscreen not needed in Southern states/New Zealand unless near highly reflective surfaces such as snow or water. It may not be possible to maintain vitamin D levels through sun exposure alone in southern states of Australia/New Zealand
		Encourage active outside play or physical activity during and after school/preschool
�� �� Pregnancy/ Adults	�� Summer	6-7 minutes with arms (or equivalent area) exposed mid-morning or mid-afternoon most days of the week, avoid sunburn,�� Full sun protection with sunscreen/hat/clothing/shade and sunglasses recommended	15-50 minutes with arms (or equivalent area) exposed mid-morning or mid-afternoon most days of the week.�� Avoid sunburn. Intermittent sun exposure without sunscreen can be tolerated but hat and sunglasses still recommended.
	�� Winter	7-40 minutes exposure (depending on latitude) with face arms, and hands exposed at lunchtime most days of the week. If UV index <3, sunscreen not required��unless in alpine regions, outside for extended periods or near highly reflective surfaces such as snow/water	Depends on latitude.�� Sunscreen not needed in Southern states/New Zealand unless near highly reflective surfaces such as snow or water.�� It may not be possible to maintain vitamin D levels through sun exposure alone in southern states of Australia/New Zealand

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Last Updated September 2020

Reference List

Australian Government National Health and Medical Research Council and Ministry of Health Manatu Hauora, 2014, Nutrient Reference Values for Australia and New Zealand,�� Canberra, viewed May 2020, <>

Holick, MF 1995, 'Environmental factors that influence the cutaneous production of vitamin D', The American journal of clinical nutrition, vol 61, no 3 Suppl, pp. 638S-45S

Hollis, BW et al 1981, 'Vitamin D and its metabolites in human and bovine milk', The Journal of Nutrition, vol 111, no 7, pp. 1240-8

Huynh, J et al 2017, 'Vitamin D in newborns. A randomised controlled trial comparing daily and single oral bolus vitamin D in infants', J Paediatr Child Health, vol53, no 2, pp. 163-69

Libon, F et al 2017, 'Sunscreens block cutaneous vitamin D production with only a minimal effect on circulating 25-hydroxyvitamin D', Arch Osteoporos, vol 12, no 1, pp. 66

Munns, CF et al 2016, 'Global Consensus Recommendations on Prevention and Management of Nutritional Rickets', Horm Res Paediatr, vol 85, no 2, p. 83-106

Osteoporosis Australia 2013, Calcium consumer guide, Sydney: Osteoporosis Australia, viewed May 2020, <>

Paxton, GA et al 2013, 'Vitamin D and health in pregnancy, infants, children and adolescents in Australia and New Zealand: a position statement', The Medical journal of Australia, vol 198, no 3, pp. 142-3

Ross, CA et al 2010, 'Dietary references intakes for calcium and vitamin D' in�� Committee to Review Dietary Reference Intakes for Calcium and Vitamin D, Food and Nutrition Board, Institute of Medicine, National Academies Press, Washington

Springbett, P et al 2010, 'Photoprotection and vitamin D status', J Photochem Photobiol B, vol 101, no 2, pp. 160-8

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