• General: weight loss, temporal and proximal muscle wasting, decreased skin-fold thickness
• Skin, hair, and nails: easily plucked hair (protein); sparse hair (protein, biotin, zinc); coiled hair, easy bruising, petechiae, and perifollicular hemorrhages (vit. C); “flaky paint” rash of lower extremities (zinc); hyperpigmentation of skin in exposed areas (niacin, tryptophan); spooning of nails (iron)
• Eyes: conjunctival pallor (anemia); night blindness, dryness, and Bitot spots (vit. A); ophthalmoplegia (thiamine)
• Mouth and mucous membranes: glossitis and/or cheilosis (riboflavin, niacin, vit. B₁₂, pyridoxine, folate), diminished taste (zinc), inflamed and bleeding gums (vit. C)
• Neurologic: disorientation (niacin, phosphorus); confabulation, cerebellar gait, or past pointing (thiamine); peripheral neuropathy (thiamine, pyridoxine, vit. E); lost vibratory and position sense (vit. B₁₂)
• Other: edema (protein, thiamine), heart failure (thiamine, phosphorus), hepatomegaly (protein)

Laboratory findings in protein malnutrition include a low serum albumin, low total iron-binding capacity, and anergy to skin testing. Specific vitamin deficiencies also may be present.