Nutritional deficiencies can often worsen health outcomes (whether a disorder is present or not), and some disorders (eg, malabsorption) can cause nutritional deficiencies. Also, many patients (eg, older patients during acute hospitalization) have unsuspected nutritional deficiencies that require treatment. Many medical centers have multidisciplinary nutrition support teams of physicians, nurses, dietitians, and pharmacists to help the clinician prevent, diagnose, and treat occult nutritional deficiencies.
Overnutrition may contribute to chronic disorders, such as cancer, hypertension, obesity, diabetes mellitus, and coronary artery disease. Dietary restrictions are necessary in many hereditary metabolic disorders (eg, galactosemia, phenylketonuria).
Evaluation of Nutritional Status
Indications for nutritional evaluation include the following:
Nutritional status should be evaluated routinely as part of the clinical examination for
Evaluating general nutritional status includes history, physical examination, and sometimes tests. If undernutrition is suspected, laboratory tests (eg, albumin levels) and skin tests for delayed hypersensitivity may be done. Body composition analysis (eg, skinfold measurements, bioelectrical impedance analysis) is used to estimate percentage of body fat and to evaluate obesity.
History includes questions about dietary intake, weight change, and risk factors for nutritional deficiencies and a focused review of systems (see table Symptoms and Signs of Nutritional Deficiency). A dietitian can obtain a more detailed dietary history. It usually includes a list of foods eaten within the previous 24 hours and a food questionnaire. A food diary may be used to record all foods eaten. The weighed ad libitum diet, in which the patient weighs and writes down all foods consumed, is the most accurate record.
Symptoms and Signs of Nutritional Deficiency
Area/System |
Symptom or Sign |
Deficiency |
General appearance |
Wasting |
Energy |
Skin |
Rash |
Many vitamins, zinc, essential fatty acids |
Rash in sun-exposed areas |
Niacin (pellagra) |
|
Easy bruising |
||
Hair and nails |
Thinning or loss of hair |
|
Premature whitening of hair |
||
Spooning (upcurling) of nails |
||
Eyes |
Impaired night vision |
|
Corneal keratomalacia (corneal drying and clouding) |
||
Mouth |
Cheilosis and glossitis |
Riboflavin, niacin, pyridoxine, iron |
Bleeding gums |
||
Extremities |
Edema |
|
Neurologic |
Paresthesias or numbness in a stocking-glove distribution |
Thiamin (beriberi) |
Tetany |
||
Cognitive and sensory deficits |
Thiamin, niacin, pyridoxine, vitamin B12 |
|
Dementia |
||
Musculoskeletal |
Wasting of muscle |
Protein |
Bone deformities (eg, bowlegs, knocked knees, curved spine) |
||
Bone tenderness |
||
Joint pain or swelling |
||
Gastrointestinal |
Diarrhea |
Protein, niacin, folate, vitamin B12 |
Diarrhea and dysgeusia |
||
Dysphagia or odynophagia (due to Plummer-Vinson syndrome) |
||
Endocrine |
Thyromegaly |
A complete physical examination, including measurement of height and weight and distribution of body fat, should be done. Body mass index (BMI)—weight(kg)/height(m)2, which adjusts weight for height (see table Body Mass Index), is more accurate than height and weight tables. There are standards for growth and weight gain in infants, children, and adolescents (see Physical Growth of Infants and Children).
Body Mass Index (BMI)
Distribution of body fat is important. Disproportionate truncal obesity (ie, waist/hip ratio > 0.8) is associated with cardiovascular and cerebrovascular disorders, hypertension, and diabetes mellitus more often than fat located elsewhere. Measuring waist circumference in patients with a BMI of < 35 helps determine whether they have truncal obesity and helps predict risk of diabetes, hypertension, hypercholesterolemia, and cardiovascular disorders. Risk is increased if waist circumference is > 102 cm (> 40 in) in men or > 88 cm (> 35 in) in women.