Nutritional Deficiencies
Causes of weight loss and malnutrition
The syndrome of malnutrition can be a primary compliant or secondary to another illness. The primary reason for malnutrition is a negative balance between dietary intake and physical needs. There are three major underlying factors: lack of food, infectious disease, and caring practices for dependents. These elements seldom occur in isolation and they often reinforce each other.
Infections: malnutrition is both a cause and a consequence of infection. The malnourished become immunosuppressed and so the infections last longer and are more severe. Infections can lead to malabsortion and diarrhea (Giardia, Strongyloides). Infections deplete body stores of vitamin A, C, E. Infection create iron deficiency (hookworm, HIV, tuberculosis)
Measuring malnutrition
Malnutrition is assessed by a combination of clinical features and body measurements.
Indicators used are: wasting (body mass index), stunting (height fore age), wasting and stunting combined (weight for age)
- BMI = weight (kg) / height (m^2) <18.5 increased likelihood of illness
Specific Nutrient deficiencies and their signs/symptoms
| Nutrients | Source | Function | Sign/symptoms during deficiency |
| Iron | Heme-iron = blood, flesh animals Non-Heme iron = green leafy plants, eggs, milk (poorly absorbed but enhanced by vitamin C) | Carries oxygen in hemoglobin | Iron-deficiency anemia (heavy blood loss, hook worms, poor intake) |
| Iodine | Soil, iodized salt, avoid itrogenenic cassaca and cabbage | Formation of thyroid hormones | Hypothyroid (goiter), cretinism (MR, stunted growth) |
| Vitamin A | Animal products (liver), red and yellow fruits | Cell differentiation, rhodopsin production in retina | blindness |
| Vitamin D | Animal products (liver) | Stimulates intestinal calcium absorption, bone formation | Malabsoption of ca, rickets in children, osteomalacia in adults |
| Vitamin K | Dark green vegetables | Enables clotting factors | Easy bruising, bleeding |
| Thiamin(vitamin B1) | Yeast, unrefined cereals, grains, absent in polished white rice | Carbohydrate metabolism, CNS function | Beri-beri: Dry: mixed sensory and motor peripheral neuropathy Wet: high-output RHF |
| Riboflavin(vitaminB2) | Meat, dairy, fish, eggs | Oxidative metabolism | Angular stomatitis, glossitis, cracking and peeling skin |
| Niacin(precursor tryptophan) | Eggs, dairy, meat | Glycolysis, fatty acid metabolism, respiration | Pellagra (dermatitis, diarrhea, dementia) |
| Folate | Green leaves, nuts | DNA synthesis | Macrocytic anemia |
| Vitamin B6 (pyridoxine) | Animal products, nuts | Protein metabolism, formation of neurotransmitters | Peripheral neuropathy, sideroblastic anemia |
| Vitamin B12(cobalamin) | Animal products, absorption requires intrinsic factor | DNA synthesis, degradation of fatty acids | Pernicious anemia, macrocytic anemia, glossitis, peripheral neuropathy |
| Vitamin C | Citrus fruits, vegetables (baobab, mangoes, oranges) | Formation of protein cross-links in collagen, anti-oxidant | Scurvy (gum bleeding, bruises, poor wound healing) |
Treatment of malnutrition
-Whenever possible, use the gastrointestinal tract for feeding (maintains integrity, no atrophy)
-moniter for refeeding syndrome in severely malnourished patients – hypoPhos, hypoK, hypoMag, heart failure exacerbation, arrythmias, glucose intolerance (treat with small, frequent meals, frequent lab checks and cardiac monitoring)
-replace GI losses with IV fluids (GI losses = diarrhea, vomiting)
-treat any underlying infections
-if patients has signs/symptoms of specific nutritional deficiency, replace that nutrient orally
Nutritional Deficiencies Clinical Cases
Case 1
16 yo female with no past medical history presents to the hospital with complaints of general body weakness. She says that the weakness has been present for many months. She also complains of loose watery diarrhea for over 2 months. Her mother tells you that she has not been acting herself and will not remember things often.
She denies fevers, chills, shortness of breath, chest pain, nausea or vomiting.
Her blood pressure is 90/40 and heart rate 92. Her respiratory rate is 22 and she is afebrile.
On exam you note a thin young girl appearing younger than her stated age.
Her pulmonary exam is normal, no wheezes with good air movement.
Her heart exam is also normal, no murmurs. Her abdomen is soft with no tenderness. You do noticed a dry erythematous rash on her lower and upper extremities. There are numerious excoriations around the rash.
1. What is the most likely diagnosis?
a. Niacin Deficiency
2. What are the constellation of symptoms called in this disease process?
a. Pellagra
