Biochemical methods

Human Nutrition 3(3+0)
Lesson 47 : Assessment of Nutritional Status

Biochemical methods

Biochemical methods involve estimating the level of the nutrient in blood or urine. These methods yield reliable data regarding the nutritional status of the individual with respect to the specific nutrient estimated. Biochemical studies which have been used in nutrition surveys are listed in table.

Advantages of Biochemical Method

  • Useful in the detection of early changes in body metabolism & nutrition before the appearance of overt clinical signs.
  • Precise, accurate and reproducible.
  • Useful to validate data obtained from dietary methods for example comparing salt intake with 24-hour urinary excretion.

Limitations of Biochemical Method

  • Time consuming
  • Expensive
  • Cannot be applied on large scale
  • Needs trained personnel & facilities

Table: Biochemical parameters suitable for assessment in nutrition surveys


Nutrient deficiency

Constituents in blood

Constituents in urine

1 Protein

Total serum protein Serum albumin

Total urea, Total creatinine Hydroxyproline.
2 Vitamin A

Serum vitamin A
Serum carotene

3 Vitamin D Serum inorganic P
Serum alkaline phosphatase in infants and weaned infants.
4 Ascorbic acid/vit C Serum ascorbic acid
W.B.C ascorbic acid
Urinary ascorbic acid
Load test
5 Thiamine R.B.C transketolase activity
Blood pyruvate
Urinary thiamine
Load test
6 Riboflavin R.B.C. riboflavin Riboflavin in urine
7 Niacin --- Load test /urinary excretion of N-methyl nicotinamide pyridine, load test
8 Iron Haemoglobin in blood Serum iron
9 Iodine Protein bound iodine Urinary iodine
Last modified: Wednesday, 15 February 2012, 10:39 AM