In recent posts, we have been focussing on anthropometric assessment methods. In this post we will address several examples of another nutrition assessment method- biochemical nutrition assessment.
Biochemical assessment involves the use of laboratory indices to detect any potential abnormalities or risk groups that may need nutrition attention. The interpretation of laboratory values requires careful examination and accuracy. Laboratory values are important in detecting possible nutrient deficiencies such as vitamin A ,D, iron and selenium. Certain established ranges of laboratory measures serve as important indices for one’s vitamin status. The vitamin D normal range, for example is between 30-70 g/ml – lower values may indicate osteoporosis, osteomalacia or hypocalcaemia while increased values may indicate hypercalciuria or hypercalcaemia.
Laboratory tests are also performed to determine one’s haematologic status through the evaluation of indices such as:
- Haemoglobin-normal range is at 3-18g/100dL for males and 12-16g/100dL for females
- Ferritin– normal range is at 12-300ug/L for males and 10-150ug/L for females. Though higher values indicate iron excess while lower values indicate protein or iron decrease. Values are greater among post menopausal women and men.
- Mean Corpuscular Value (MCV) -80-95 mm3. Lower values imply iron deficiency anaemia while higher values imply pernicious anaemia.
- Haematocrit (HCT)– normal range is at 42% – 52% for males and 37% – 47% for females
Biochemical assessment is also useful in determining protein status using the following indicators :
- Albumin-normal range between 3.5 – 5g/dL
- Pre-albumin normal range between 19 – 43 mg/dL
- Urea nitrogen –normal range between 10-20 mg/dL
- Transferrin -normal range between 200-400mg/dL
- Total Protein-normal range between 6.4-8.3mg/dL
Although, it is important to note all these indicators of protein status except for total protein assess morbidity, severity of infection and inflammatory metabolism rather than nutrition status. Total protein is more of an indicator of nutrition status as it indicates either dehydration or multiple myeloma when higher than normal range or malnutrition, nephrosis , overhydration or acute liver failure when lower than normal range.
Lipid profile involves measuring the level of triglycerides and cholesterol in your blood :
- Triglycerides -normal range< 150 mg/dL
- LDL cholesterol normal range <100 mg/dL.
- HDL cholesterol – between 40 – 60 mg/dL
Tests can also be performed to determine blood glucose levels:
- Fasting plasma glucose–normal range <100 mg/dL
- Oral Glucose Tolerance Test (OGTT ) -normal range<140 mg/dL
- A1C Test –normal range between 4.5 to 5.5 %
Biochemical assessment involves the use of laboratory tests to assess nutritional status. The interpretation of laboratory values requires careful examination and accuracy. This method can determine protein status and haematologic status and detect potential nutrient deficiencies.