Vitamins

  • Vitamin

    Function

    Dietary sources

    Causes deficiency

    Risk groups, prevalence

    Clinical findings

    Screening and management

    A
    Forms - retinol, retinal, retinoic acid or retinyl ester

     

    Fat soluble vitamin - Epithelial cell function, vision, immune function, embryo development

    Preformed in animal foods (liver, fish, butter, cheese, whole milk, egg yolk), carotenoids in plant based foods (orange/ yellow fruits and vegetables)

    Low vitamin A content in breast milk, restricted food access, alcoholism

    Infants, children, pregnant/lactating women, alcoholism
    Intestinal failure, biliary, pancreatic disease, PEM
    Anecdotal reports Rohingya populations

    Dry eyes, night blindness, increased infections, hyperkeratotic rash (goose bump rash), Bitot’s spots on conjunctivae, corneal ulceration and scarring, blindness; anaemia, poor growth

    Screen if:
    Clinical signs deficiency
    Post arrival in children from refugee camps or situations with poor access to food, or
    where fat malabsorption suspected. See:
    Vitamin A guidelines

    B1

    Thiamine

    Water soluble vitamin - role in oxidative phosphorylation and pentose phosphate pathway (carbohydrate metabolism)

    Cereal foods, including wheat germ, wheat bran, wholemeal flour, pork, beef, liver, kidney, legumes, nuts, yeast extract, (Vegemite), nuts, peas, sesame seeds

    Rice based diets, foods with thiaminases/anti-thiamine compounds, ­req’mts pregnancy lactation

    Endemic in areas with rice based diets, anecdotal reports in Karen refugee children pre-arrival with polished rice diet
    Alcoholism, HIV, jejunal disease (site absorption)

    Weakness with intercurrent illness, anorexia; irritability; beri-beri - cardiovascular symptoms and/or symmetric peripheral neuropathy, Wernicke encephalopathy (confusion, reduced consciousness, ataxia, ophthalmoplegia) Korsakoff syndrome (memory disorder, confabulation)  - beri-beri and WKS do not usually occur together

    Screen if:
    History weakness with intercurrent illness
    Thiamine dosing

    Water-soluble vitamin - coenzyme in TCA, fatty acid synthesis, synthesis of B3, conversion B6 to active form

    Milk, dairy, fortified bread/cereal, eggs, pulses, green vegetables, almonds, yeast extract

    Corn based diets

    Corn based diets (Africa, India, parts of China)

    Angular stomatitis, cheilitis, glossitis, dermatitis, elevated homocysteine, normocytic anaemia

    Not usually measured
    Riboflavin dosing

    B3
    Niacin
    Nicotinic acid and nicotinamide

    Water soluble vitamin - coenzyme dehydrogenase-reductase reactions including glycolysis, and fatty acid metabolism

    Beans, milk, beef, pork, liver, eggs, wheat,

    Restricted food access
    Maize based diets

    Restricted food access, rice based diets

    Pellagra – dermatitis (hyperpigmented skin and mucosal changes, photosensitivity), diarrhoea, dementia, glossitis, anorexia, weakness, irritability

    Not usually measured
    Niacin dosing – see NRV

    Part of coenzyme A, reactions involving CHO, protein and lipid metabolism

    Organ meat, chicken, beef, potatoes, oats, grains, tomatoes, eggs, peanuts, green vegetables

    Restricted food access

    Restricted food access, rice based diets

    Very rare – gastrointestinal Sx, depression, irritability, burning sensation feet, low BSL,

    Not usually measured
    B5 dosing – see NRV

    B6

    Pyridoxine

    Cofactor enzymes in aminotransferase reactions inc. aminolevulinic acid and serotonin

    All food groups esp. legumes, nuts, wheat, meat, bananas

    Restricted food access
    Isoniazid treatment (­urine excretion)

    Restricted food access, rice based diets

    Microcytic, hypochromic anemia (¯heme synthesis), dermatitis, cheilitis, stomatitis, peripheral neuropathy, seizures, ¯AST and ALT

    Not usually measured
    Pyridoxine dosing

    B7
    Biotin

    Water-soluble vitamin, cofactor for carboxylases

    Organ meat, eggs, dairy, synthesis by intestinal bacteria

    Anticonvulsants, hemodialysis, parenteral nutrition large amounts raw egg whites

    Haemodialysis, PN dependent patients

    Dermatitis, glossitis, alopecia, poor growth, ataxia, weakness, depression and seizures

    Not usually measured
    Biotin dosing

    B12
    Cyanocobalamin

    Water-soluble vitamin - DNA synthesis, branched chain amino acid metabolism

    Animal based foods, muscle meat, fish, eggs, dairy, yeast, synthesis by intestinal bacteria

    Vegan diets

    Vegans, restricted food access
    Breastfed infants of mothers with deficiency
    Gastric atrophy
    People from Iran, Iraq, Afghanistan, Bhutan

    glossitis, stomatitis, weakness, Megaloblastic anaemia, hypersegmented neutrophils, ­homocysteine, ­methylmalonic acid

    Consider screen – Iran, Bhutan, Afghanistan, Iran
    Screen in exclusively breastfed infants where maternal deficiency suspected, or where deficiency suspected
    Vitamin B12 guideline

    C
    Ascorbic acid

    Water-soluble vitamin, antioxidant collagen synthesis, neurotransmitter and carnitine production, enzyme f’n

    Citrus fruits, broccoli tomatoes, potatoes, berries, guava, mango, capsicum, pawpaw, parsley, pineapple, spinach and cabbage

    Diets without fruit and vegetables

    Restricted eating/food access, sometimes seen in autism

    ¯absorption iron, ¯collagen formation,¯immune function, ¯wound healing
    Scurvy: perifollicular haemorrhage, gum bleeding, bruising, oedema, weakness, bony changes on XR

    Screen if clinical signs deficiency, poor fresh food access
    Vitamin C dosing

    D
    Cholecalciferol (D3) or ergocalciferol (D2)

    Fat soluble vitamin - calcium and phosphate balance
    Bone health, emerging evidence influences cardiovascular health, pregnancy outcomes and immunity/atopy

    Skin synthesis - most important source of vitamin D for all ages, diet is a poor source of vitamin D for all ages, (generally 10 – 25%) – found in some fatty fish, added to margarine, breast milk content ~25 IU/L, formula 380 – 520 IU/L

    Lack of skin exposure to UVB in sunlight
    Dark skin
    Conditions/medications affecting D metabolism
    Infants: maternal deficiency and BF with one or more other risk factors

    Lack of skin exposure to sun, dark skin
    Medications/conditions affecting vit D metabolism inc obesity
    Exclusively breastfed Infants born to deficient mothers, who have at least 1 other risk factor

    Bone pain
    Muscle pain
    Delayed dental eruption
    Poor growth
    Late motor milestones
    Rickets

    Screen if at least one risk factor
    Vitamin D guideline

    E
    Alpha-tocopherol and other forms

    Fat soluble vitamin - antioxidant esp. for PUFA, protects cell membranes, reg’n prostaglandin synthesis

    Plant oils, including wheat germ, sunflower, canola, olive, less in corn oil and soy oil

    Fat malabsorption

    Intestinal failure, biliary, pancreatic disease, PEM

    Peripheral neuropathy, reduced DTR, impaired balance/gait, myopathy, pigmented retinopathy, RBC fragility (acanthocytes) and haemolysis

    Screen if fat malabsorption suspected
    Vitamin E dosing

    Folate

    Water soluble vitamin, DNA/RNA synthesis and amino acid metabolism

    Green leafy vegetables, fortified bread/cereals

    Restricted food access, Methotrexate, phenytoin and sulfasalazine, cotrimoxazole antagonize folate utilization

    Restricted food access, lack of fresh food intake

    Glossitis, stomatitis, poor growth and fetal neural tube defects, Macrocytic anemia, hypersegmented neutrophils

    Screen if clinical deficiency suspected, poor fresh food access, macrocytosis,

    K
    Phytomenadione

    Clotting factors 2, 7, 9, 10 protein C and S; cofactor for g-glutamyl carboxylase

    Green leafy vegetables, vegetable oils (especially soy) eggs, meat, dairy

    Liver failure

    Intestinal failure, biliary, pancreatic disease, PEM

    Bleeding/bruising

    Not measured, check INR
    Vitamin K dosing