Malnutrition will often be noticeable to the doctor's trained eye before it causes significant abnormalities in laboratory test results. During physical examinations, a health practitioner will evaluate an individual's overall appearance: their skin and muscle tone, the amount of body fat they have, their height and weight, and their eating habits. In the case of infants and children, doctors will look for normal development and a normal rate of growth.
If there are signs of malnutrition, a health practitioner may order general laboratory screening tests to evaluate a person's blood cells and organ function. Additional individual tests may be ordered to look for specific vitamin and mineral deficiencies. If general malnutrition and/or specific deficiencies are diagnosed, then laboratory testing may be used to monitor the response to therapy. A person who has malnutrition because of a chronic disease may need to have his or her nutritional status monitored on a regular basis.
Hospitalized patients are often assessed for nutritional status prior to or at the time of admission. This may include a history, an interview by a dietician, and laboratory tests. If the results of these tests indicate possible nutritional deficits, patients may be provided nutritional support prior to a surgery or procedure and be monitored regularly during recovery.
Laboratory tests may include:
For general screening and monitoring:
For nutritional status and deficiencies:
- Iron tests such as serum iron, TIBC, and ferritin
- Vitamins and trace minerals such as B12 and folate, vitamin A, vitamin D, vitamin K, B vitamins, calcium, and magnesium
- Prealbumin: although commonly used as a marker of malnutrition, levels of this protein may be affected by a number of conditions other than malnutrition. Research is continuing in order to better understand the role(s) of prealbumin in the body, especially the reasons for changes observed during illness, and the clinical utility of prealbumin testing.
- Albumin has been used in the past along with or instead of prealbumin to evaluate nutritional status but now is more often used to screen for and help diagnose liver or kidney disease.
- Leptin: suppressed levels may indicate malnutrition in some patients; this test is not widely available.
Imaging and radiographic scans may be ordered to help evaluate the health of internal organs and the normal growth and development of muscles and bones. These tests may include:
- CT (Computed Tomography)
- MRI (Magnetic Resonance Imaging)
For more on these, visit RadiologyInfo.org.