Micronutrient deficiency

  • See also

    Iron deficiency
    Vitamin D deficiency

    Key Points

    1. Consider micronutrient deficiencies in all children with diets which are highly restricted in variety and balanced nutritional content due to neurodevelopmental conditions eg ASD, cognitive impairment
    2. Normal growth parameters do not exclude possible micronutrient deficiency
    3. Micronutrient deficiencies can be associated with permanent physical disabilities (eg blindness) or death
    4. Clinical features of micronutrient deficiency may be subtle, consider in children with highly restricted diets presenting with non-specific symptoms  


    Micronutrient deficiency may occur in children who have sufficient caloric intake for acceptable growth, but a diet significantly restricted in food variety. This can occur in the absence of an underlying medical condition or eating disorder, and differs from ‘fussy eating’, which is common in early childhood and generally resolves over time 

    These patterns of eating behaviour are often seen in children with:

    • Neurodevelopmental conditions including autism spectrum disorder
    • Avoidant restrictive food intake disorder (ARFID)
    • Multiple food allergies
    • Elective dietary restrictions due to cultural, religious, or environmental reasons

    Children with underlying medical conditions impacting the absorption or utilisation of micronutrients should undergo management in consultation with relevant specialist services



    • Diet highly limited in variety eg missing food groups, less than 10 foods/food types regularly consumed, minimal meal to meal variability
    • Dietary patterns predisposing to vitamin and mineral deficiencies eg veganism
    • Consider reviewing diet in context of Australian Healthy Eating Guidelines
    • Clinical features suggestive of specific micronutrient deficiency (see below)
    • History of previous micronutrient deficiency
    • Use of vitamin and mineral supplements
    • Suspected or actual diagnosis of neurodevelopmental disorder eg ASD, cognitive impairment


    • General assessment for micronutrient deficiency should be performed including checking for skin changes (including pallor), dry eyes, oral mucosa and gum changes, goitre, bony deformity, neuropathy, hair or nail changes
    • Growth measurements should be routinely performed, but noting that child may have normal growth for age and sex or even be overweight
    • Consideration should be given to the following clinical features associated with specific micronutrient deficiencies


    Clinical features of deficiency

    Risks for deficiency

    Vitamin A

    Xerophthalmia: night blindness, dry conjunctiva, corneal ulceration, blindness

    Dry skin and pruritis

    Increased susceptibility to infection

    Poor growth

    Malabsorption eg exocrine pancreatic insufficiency, chronic liver disease, short bowel syndrome, inflammatory bowel disease

    Maternal deficiency

    Some refugee populations

    Vitamin B1

    Fatigue, irritability, apathy, nausea, abdominal discomfort

    Dry beriberi (symmetric peripheral neuropathy) 

    Wet beriberi (cardiac failure)

    Wernicke encephalopathy: confusion, reduced consciousness, ataxia, ophthalmoplegia 

    Korsakoff syndrome: confusion, amnesia 

    White rice-based diets


    Some refugee populations   

    Vitamin B3

    Anorexia, vomiting, abdominal pain

    Glossitis, cheilitis

    Pellagra: triad of dermatitis, diarrhoea and confusion

    Late symptoms include apathy, weakness, headache, confusion, irritability, anxiety, tremor, depression

    Corn based diets


    Vitamin B9

    Clinical signs of anaemia

    Macrocytic anaemia and hyper-segmented neutrophils on full blood count

    Glossitis, oral ulcers

    Fatigue, slow growth

    Lack of fresh food in diet


    Medications eg phenytoin, phenobarbital, methotrexate, long-term NSAID use   

    Vitamin B12

    Clinical skins of anaemia

    Macrocytic anaemia and hyper-segmented neutrophils on full blood count

    Irritability, developmental delay, developmental regression, involuntary movements, peripheral neuropathy

    Glossitis, oral ulcers

    Skin changes eg hyperpigmentation, vitiligo

    Vegan and vegetarian diet

    Some refugee populations

    Gastrointestinal disease

    Exclusively breastfed infants of mothers with Vitamin B12 deficiency

    Vitamin C
    (Ascorbic acid)

    Scurvy: skeletal fractures and joint pain, poor wound healing, fatigue, weight loss, gingival inflammation with gum bleeding, petechiae, ecchymosis, purpura, dry eyes and mouth, corkscrew hair 

    Diets without fruit and vegetables

    Vitamin D

    Rickets: lower limb deformities, enlargement of wrists and ankles, protruding abdomen, delayed gross motor development, generalised musculoskeletal pain

    Hypocalcaemia: may present with seizures and tetany

    Lack of skin exposure to sun

    Dark skin


    Liver/renal failure

    Gastrointestinal disease

    Exclusively breastfed infants of mothers with vitamin D deficiency

    Vitamin E

    Decreased muscle mass

    Weakness, unsteady gait


    Vitamin K

    Excessive bleeding/bruising




    Peripheral neuropathy 

    Prolonged total parenteral nutrition




    Other signs and symptoms of hypothyroidism

    Extremely rare unless immigrated from high-risk areas eg inland Asia or Africa


    Clinical signs of anaemia: pallor, irritability, anorexia, fatigue

    Microcytic anaemia on full blood count

    Behavioural disturbance, impaired cognitive function, decreased memory, impaired learning and concentration

    Pica (eating non-food items)

    Vegetarian or vegan diet

    High milk intake

    Gastrointestinal disease

    Heavy menstrual loss

    Maternal iron deficiency


    Low birth weight  




    Shortened fingers and toes

    Prolonged total parenteral nutrition


    Acrodermatitis enteropathica: Periacral, periorificial dermatitis, diarrhoea, alopecia

    Depressed mood, apathy, and emotional disturbances in older children


    Total parenteral nutrition

    Vegetarian diet


    • Children at risk based on history should be strongly considered for investigations
    • Consider investigations even in asymptomatic children as some complications of micronutrient deficiency are irreversible
    • Symptomatic children should be prioritised for urgent assessment and initiation of treatment or even empirical supplementation
    • Dietician referral to assist in assessment and management (eg dietary change, supplementation) is recommended
    • Any patients with identified micronutrient deficiency should have other possible diagnoses considered in addition to dietary causes


    • Given the challenges and distress caused by blood collection in many children at risk for micronutrient deficiency, consider performing all first line laboratory investigations with one blood collection unless only a specific deficiency is suspected based on history or examination
    • Opportunistic testing during sedation or anaesthesia should also be considered to minimise distress and trauma
    • Tests may also need to be prioritised based on sample volume available
    • Estimated blood volume required for first line investigations is 10-15 mL whole blood, with specific collection details to be confirmed with local laboratory

    First line investigations


    • FBE 
    • UEC, LFT, calcium, magnesium, phosphate 
    • Iron studies 
    • Vitamin A (light sensitive, cover tube with foil)
    • Thiamine  
    • Folate 
    • Vitamin B12 
    • Vitamin C 
    • Vitamin D (see flowchart for criteria)  
    • Zinc 

    Second line investigations to consider if specific risks for deficiency or clinical features identified


    • Coagulation Profile (as marker of Vitamin K deficiency) 
    • Thyroid function test (as marker of iodine deficiency)
    • Vitamin E 
    • Selenium 
    • Copper 


    • Vitamin B3


    • Specific micronutrient deficiencies should be managed with supplementation
    • Dosing suggestions and practical advice are provided below for more common deficiencies but consultation with local guidelines or pharmacist should be considered, particularly if multiple micronutrient deficiencies are identified


    Dosing advice


    Practice advice

    Common food Sources

    Vitamin A

    Level 0.35-0.7 micromol/L (or low for age)

    • <6 months: 50,000 IU oral stat
    • 6-12 months: 100,000 IU oral stat
    • >12 months: 200,000 IU oral stat

    Repeat dose at 6 months if risk factors persist

    Level <0.35 micromol/L or Xerophthalmia
    Dose on day 1, 2 and 14

    • <6 months: 50,000 IU oral
    • 6-12 months: 100,000 IU oral
    • >12 months: 200,000 IU oral


    • Capsules (5,000 IU and 10,000 IU)
    • Drops (5000 IU/0.2 mL)


    • 100,000 IU per dose, requires Special Access Scheme (SAS) Approval

    Toxicity occurs at chronic daily intakes >6,000 microg

    Repeat levels after treatment

    Liver, oily fish, dairy products, eggs, orange fruits and vegetables, green leafy vegetables

    Vitamin B1

    Subclinical deficiency

    •  2mg/kg (rounded to nearest 25 mg, max 100 mg) oral once daily for 6 weeks

    If symptomatic, discuss parenteral treatment with local paediatric team   


    • Tablet (100 mg)

    Intravenous/ Intramuscular

    • Seek local pharmacist advice

    Low toxicity risk

    Repeat levels after treatment

    Red meats, poultry, fish, shellfish, eggs, nuts and seeds, fortified breads and cereals

    Vitamin B9

    Treatment of folate deficiency anaemia

    • 1-12 months: 0.5 mg/kg (maximum 5 mg) once daily for 4 months
    • >12 months: 5 mg oral once daily for 4 months, then 5 mg every 1-7 days

    Prevention of folate deficiency if ongoing risk factors

    • 1 month: 12 years, oral 2.5-10 mg once daily
    • 12-18 years: 5-10 mg oral once daily


    • Tablets (5 mg)

    Injectable forms available. Seek local pharmacist advice

    Low toxicity risk

    Repeat levels after treatment

    Exclude Vitamin B12 deficiency prior to dosing

    Supplementation can reduce serum levels of some antiepileptics (Phenytoin, Carbamazepine, Valproate)

    Offal, oily fish, fortified cereals, breads and pasta, lentils and legumes, green vegetables, root vegetables

    Vitamin B12

    Subclinical deficiency

    • 100 microg oral once daily

    If symptomatic or unable to tolerate oral treatment, discuss parenteral treatment with local paediatric team   

    Oral (Cyanocobalamin)

    • Tablet (100 microg and 1000 microg)
    • Sublingual wafer (1,000 microg)
    • Sublingual spray (500 microg, limited evidence for use)

    Intramuscular (Hydroxocobalamin)

    • 1,000 microg

    Low toxicity risk

    Repeat levels after treatment

    High dose oral replacement may be considered in place of intramuscular if no features of malabsorption


    Shellfish, fish, red meats, poultry, eggs, dairy, fortified breads and cereals

    Vitamin C
    (Ascorbic acid)


    • 100 mg tds (oral, IV, IM) for one week, then 100mg oral once daily for several weeks until patient is fully recovered or repeat levels normalised


    • Tablet (100 mg)
    • Liquid

    Intravenous/ Intramuscular

    • Seek local pharmacist advice

    Low toxicity risk

    Repeat levels after treatment

    Fruit, raw or steamed vegetables, fruit juice

    Vitamin D

    See vitamin D deficiency

    Oily fish, eggs, offal, fortified dairy products, fortified cereal


    See iron deficiency

    Red meats, poultry, fish, shellfish, offal, fortified cereals and breads, legumes, tofu, eggs, nuts, green leafy vegetables


    Subclinical deficiency

    • 1 mg/kg/day oral in 1-3 doses, repeat levels after 1 month

    Acrodermatitis enteropathica

    • 3 mg/kg/day oral


    • Tablets (25 mg, 40 mg)
    • Capsules (can be opened and dispersed)
    • Liquid

    Toxicity can lead to copper deficiency, otherwise low toxicity risk

    Meats, shellfish, oily fish, eggs, dairy products, nuts and seeds, wholegrain breads and cereals

    • Consider the use of a multivitamin in all children at risk of micronutrient deficiency. Seek advice from dietician on choice and dosage of multivitamins meeting recommended vitamin and mineral daily intake for age, while considering tolerability of different formulations eg liquid, tablet, powder
    • Occupational or speech therapy services can assist with administration strategies and addressing underlying food aversions. Specialised feeding services or feeding therapists may be available in some regions or via telehealth from larger centres
    • Children with identified micronutrient deficiency who have completed initial replacement should have management put in place to maintain sufficient nutrient intake (maintenance dosing). This should continue until such a time that the dietary risk factors have been addressed or resolved

     Consider consultation with local paediatric team when

    • Child has symptomatic micronutrient deficiency
    • Cause of micronutrient deficiency is not clear
    • Oral supplementation not successful
    • Consideration of feeding support through nasogastric tube or gastrostomy is required

    Consider transfer when

    Care required is beyond the capability of the local hospital

    Consider discharge when

    Micronutrient deficiency successfully treated, and risk factors have been addressed

    Parent information

    Healthy Eating for Children
    Nutrition – babies and toddlers
    Nutrition – school age to adolescence
    Vitamin D

    Additional notes

    Australian Government Eat for Health Resources and Nutritional Guidelines
    Nutrient reference values for age
    RCH Food and Nutrition resources
    Nutrition Education Materials Online (NEMO) | Queensland Health

    Last updated September 2023

  • Reference List

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    2. AMH Children’s Dosing Companion (online). Folic acid. Adelaide: Australian Medicines Handbook Pty Ltd; 2020 July. Available from: https://childrens.amh.net.au/
    3. AMH Children’s Dosing Companion (online). Vitamin B12. Adelaide: Australian Medicines Handbook Pty Ltd; 2020 July. Available from: https://childrens.amh.net.au/
    4. Bourne L, Mandy W, Bryant‐Waugh R. Avoidant/restrictive food intake disorder and severe food selectivity in children and young people with autism: A scoping review. Developmental medicine and child neurology. 2022;64(6):691–700. DOI: 10.1111/dmcn.15139    
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    6. Joint Formulary Committee (2021) 'Vitamin B12', in British National Formulary. Available at: https://www-medicinescomplete-com.apollo.worc.ac.uk/#/content/bnf/_970446495
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    12. Sharp WG, Berry RC, Burrell L, Scahill L, McElhanon BO. Scurvy as a sequela of avoidant-restrictive food intake disorder in autism: a systematic review. Journal of Developmental and Behavioral Pediatrics. 2020;41(5):394-405.doi:10.1097/dbp.000000000000782   
    13. Yule S, Wanik J, Holm EM, Bruder MB, Shanley E, Sherman CQ, et al. Nutritional Deficiency Disease Secondary to ARFID Symptoms Associated with Autism and the Broad Autism Phenotype: A Qualitative Systematic Review of Case Reports and Case Series. Journal of the Academy of Nutrition and Dietetics. 2021;121(3):467-92.doi:10.1016/j.jand.2020.10.017