Nutritional Deficiencies in Childhood

Nutritional Deficiencies in Childhood

Iron Deficiency

·        Commonest deficiency in worldwide

·        Marker of poor diet generally

·        Associated with:

o   Inadequate iron intake:

§  Homogenised cows milk

§  Late introduction of iron-rich foods

§  Prolonged sole breast feeding (> 6 months)

o   Intrauterine growth retardation and placental insufficiency (especially rapid catch up growth) 

o   Excess losses: chronic gut losses (eg infestation, food intolerance) and skin loss in severe ectopic eczema

·        Sources of iron:

o   Poor sources:

§  Spinach: poorly absorbed

§  Cows milk: poor source and may lead to gut bleeding

§  Breast milk: only sufficient to 4 – 6 months, but ­ absorption once food is introduced

o   Good sources:

§  Meat: haem iron well absorbed.  Especially dark red meat (eg liver) 

§  Pulses: lentils, peas, baked beans and soya beans (not green beans), but ­ gas

§  Dark fish, shell fish and spices 

o   Breast milk and vitamin C ­absorption, Cows milk and tea ¯absorption (NB some Polynesians call tea milo – so ask what sort of tea)

·        Anaemia:

o   At birth, Hb = 170, several weeks later = 105 

o   Clinical effects: tired, lethargic, irritability, slow cell mediated immunity, pica (eat anything) which may ® lead poisoning (small RBCs and anaemia)

o   Diagnosis:

§  Look for pale earlobes

§  Blood tests, iron studies etc.  MCV < 71 in child over 3 months

§  Ferritin low (but high if infection – test CRP as well and ignore ferritin if raised)

o   Serum iron – altered in presence of infection. Zinc Protoporphyrin is a new, sensitive test (Zn substituted for Fe in haem).

o   Reticulocyte count useful test of response to treatment.  Should respond within a week

·        Treatment: 

o   Find and fix cause: if diet then ® dietician. 

o   Ferrous gluconate elixir: 50 mg/kg/day (= 6mg/kg/day elemental iron) in 2 – 3 doses with fruit juice until MCV normal

Rickets

·        Usually a lack of Vitamin D.  With fear of sunburn, it is likely to increase

·        At risk: 

o  Pigmented people with low dietary vitamin D intake and low sunlight exposure. Breast milk is not a very rich source of vitamin D

o  Preterm infants with low Vitamin D intake

o  Fat malabsorption

o  Other rarer causes: anticonvulsant therapy, chronic renal disease, Ca or phosphate deficiency

·        Diagnosis: 

o  Clinical: broad wrists, tender joints, avoidance of weight bearing, bowed legs if weight bearing, bent pelvis (® obstructed labour later in life), Rickety Rosary (swelling of costochondral junctions) 

o  Lab: ­ALP, ¯PO4, Ca usually normal

o  Xray: Widened metaphysis and splaying of softened bones, generalised osteopenia

·        Treatment:

o  1-a cholecalciferol: 0.05 – 0.1 mcg/kg/day until ALP normal

o  Surgery to bones not usually necessary, even when very bent

Other deficiencies

·        Breast Milk is short of: 

o  Vitamin K (fat soluble). Deficiency ®haemorrhagic disease of the new born in first few weeks/months 

o  Vitamin B12: if mother is vegan ® CNS symptoms (fits, abnormal movements, mental retardation) + macrocytic anaemia

·        Chronic malabsorption or prolonged TPN ® Zn deficiency ® Acrodermatitis Enteropathica (rash, especially around buttocks) and immunodeficiency

·        Vitamin A deficiency: from fat malabsorption or ¯ intake ® night blindness and ­risk of complications from eg measles

·        Folic Acid: Deficiency during pregnancy ® ­ risk of neural tube defects