Pediatric Nutrition in Practice

Use of Laboratory Measurements in Nutritional Assessment 25

1

Table 1 (continued)

Test (specimen) Normal range^1 Function/description Deficiency Pitfalls to avoid

Hemoglobin
(whole blood)

0 – 8 days: 2.06 – 3.79 mmol/l

9 days: 1.66 – 3.33 mmol/l

3 months: 1.53 – 2.25 mmol/l

1 year: 1.38 – 2.14 mmol/l

3 years: 1.58 – 2.31 mmol/l

11 years: 1.72 – 2.43 mmol/l

Adult male: 1.86 – 2.48 mmol/l

Adult female: 2.17 – 2.79 mmol/l

Oxygen-carrying moiety

in RBC

Microcytic

Iron deficiency, chronic

disease

Normocytic

Chronic disease, acute

bleeding

Macrocytic

B 12 , folate deficiency

Influenced by hydration status,

nutrition and pregnancy

Iron (serum) Neonate: 17.9 – 44.8 μmol/l
Infant: 7.2 – 17.9 μmol/l
Child: 9 – 21.5 μmol/l
Adult male: 11.6 – 31.3 μmol/l
Adult female: 9 – 30.4 μmol/l

Component in heme and

cytochrome proteins

Microcytic anemia, pallor,

weakness and dyspnea

Transferrin is a sensitive

measure of body iron stores;

however, it is a negative

acute-phase protein

Lymphocytes
(whole blood)

>1,500/mm^3 Total lymphocyte count is

inversely correlated to degree

of malnutrition [6]

Magnesium
(serum)

0.63 – 1.00 mmol/l Important for neuromuscular

conduction; enzyme cofactor

Arrhythmia, tetany,

hypocalcemia and

hypokalemia

↓ by low serum albumin

↑ by hemolyzed specimens

pH (stool) >5.5 [7] Low fecal pH usually implies
carbohydrate malabsorption

Improper specimen processing

may lead to falsely low values

Phosphorus
(serum)

Neonate: 1.45 – 2.91 mmol/l

10 days to 2 years: 1.29-2.1 mmol/l

3 – 9 years: 1.03 – 1.87 mmol/l

10 – 15 years: 1.07 – 1.74 mmol/l

>15 years: 0.78 – 1.42 mmol/l

Vital for energy transfer at

cellular level

Confusion, respiratory distress,

tissue hypoxia, bone

abnormalities and ↑ alkaline

phosphatase

‘Refeeding syndrome’ is

hypophosphatemia and

hypokalemia complicating

nutritional rehabilitation of the

severely malnourished patient

Prealbumin
(serum)

Neonate: 70 – 390 mg/l

1 – 6 months: 80 – 340 mg/l

6 months to 4 years: 120 – 360 mg/l

4 – 6 years: 120 – 300 mg/l

6 – 19 years: 120 – 420 mg/l

Gauge of visceral protein

stores; half-life of 2 days

Negative acute-phase reactant

Prothrombin
time (plasma)

11 – 15 s [2] Used to assess vitamin K

sufficiency, although

better assessed with

undercarboxylated

prothrombin (PIVKA-II)

Also prolonged in liver

dysfunction, malabsorption

syndromes, prolonged

antibiotic use and warfarin

therapy

Reducing
substances
(stool)

Negative Presence suggests carbo-

hydrate malabsorption

Improper specimen processing

may lead to falsely normal

values

Retinol-binding
protein (serum)

<9 years: 10 – 78 mg/l

>9 years: 13 – 99 mg/l [2]

Gauge of visceral protein

stores; half-life of 12 h

Negative acute-phase reactant

↓ in vitamin A deficiency,

hepatic dysfunction

↑ in renal failure

Selenium
(serum)

Preterm: 0.6 – 1 μmol/l

Term: 0.8 – 1.1 μmol/l

1 – 5 years: 1.4 – 1.7 μmol/l

6 – 9 years: 1.4 – 1.8 μmol/l

>10 years: 1.6 – 2.1 μmol/l [5]

Trace mineral essential for

glutathione peroxidase

Cardiomyopathy (Keshan

disease), myositis and nail

dystrophy

Urea nitrogen
(serum)

Preterm (1st week): 1.1 – 8.9 mmol/l

Neonate: 0.7 – 6.7 mmol/l

Infant/child: 1.8 – 6.4 mmol/l

Adult: 2.1 – 7.1 mmol/l

Produced in liver from

protein degradation and

excreted renally

↓ in low-protein-intake states

↑ in high-protein diets, but also

kidney disease

Koletzko B, et al. (eds): Pediatric Nutrition in Practice. World Rev Nutr Diet. Basel, Karger, 2015, vol 113, pp 23–28

DOI: 10.1159/000360314