• Most Zinc is accumulated during the 3^rd trimester of pregnancy.
• After iron it is the most likely trace element to be deficient.

Risk Factors

• Premature birth
• Vegan/vegetarian mother (or a mother who has stopped eating red meat during pregnancy)
• Accelerated growth - growth is the major determinant of Zinc requirement
• Thiazide diuretics - hydrochlorthiazide increases excretion of Zinc
• Dexamethasone - may impair Zinc absorption
• Unusually low ALP (a Zinc dependent enzyme important for bone metabolism, which is often high in premature babies with osteopenia)
• Low albumin-Zinc is transported bound to albumin so mild hypoalbuminaemia may alter serum Zinc concentration
• Large stool or ostomy output - short bowel syndrome etc.

Signs of Zinc Deficiency

• Zinc <7.5 mmol/L is highly suggestive of deficiency (reference range 12-20) but it is acknowledged there are problems with reliability of measuring serum zinc
• Growth failure - adequate energy and protein intake
• Diminished food intake usually due to reduced ability to taste and smell - loss of appetite
• Skin lesions
• Poor wound healing
• Hair loss
• Protein synthesis
• Immune function
• If severe - diarrhoea, behaviour changes, skin lesions, poor growth

NB: The only definite method of diagnosing Zinc deficiency is to note the clinical and biochemical responses to Zinc supplementation.

Guidelines for the Treatment of Zinc Deficiency

If poor growth and serum zinc is <8 mmol/L Tsang ² recommends double or triple the RDI (1.2mg/kg/day X 2 or 3)

1. Prescribe orally - 1 to 2 mg elemental Zinc/kg/day
2. Ensure an adequate intake of Zinc from feeds; 
   • If <2.5kg Fortified EBM or Preterm formula
   • If >2.5kg Unfortified EBM or Term formula (not Soy)
3. Monitor serum Zinc weekly.
4. Treatment is continued until biochemical indexes are normal and growth has improved 

References