Pathology
Lecture 19 Nutritional Disease
1) Identify on physical examination, or on review of tissue slides or photographs,
tissue alterations resulting from deficiencies of:
A. Total calories – Marasmus is a deficiency of almost all nutrients but mostly
proteins and calories with multiple vitamin deficiencies. Present when a
malnourished child’s weight fall to <60% of normal for sex and age. It results in
stunted growth, muscular atrophy, and loss of subcutaneous fat.
B. Protein – Kwashiorkor is caused purely by a protein deficiency. Often occurs
when children are weaned and eat primarily carbohydrates. Hypoalbuminemia
results in severe edema. Fatty liver, anemia, and malabsorption due to intestinal
atrophy are also present. Characterized by stunted growth and muscle wasting
with preservation of subcutaneous fat.
C. Fat soluble vitamins
1. Vitamin A – aids in differentiation of mucus epithelial cells, enhances
immunity to infections, and maintains normal night vision. In Vitamin A
deficiency, corneal epithelium is replaced by keratinizing epithelium in small
plaques (Bitot spots), which will erode the cornea resulting in blindness.
2. Vitamin D – maintains normal calcium and phosphorous levels in the plasma.
Deficiency results in hypocalcemic tetany, osteomalacia in adults, and rickets
in children. Excess unmineralized bone matrix is deposited in epiphyseal
plates (disrupting growth) and microfractures occur from weakened bone.
3. Vitamin E – is a scavenger of free radicals. Insufficiency, although rare,
occurs with fat malabsorption, abetalipoproteinemia, immature liver and GI
tract in infants, and genetic impaired vitamin E metabolism. Damage occurs in
the nervous system causing axonal degeneration in the dorsal root ganglia and
erythrocytes causing a shorter half-life.
4. Vitamin K – is a cofactor for liver microsomal carboxylase which converts
glutamyl residues to gamma-carboxyglutamates. Clotting factors VII, IX, and
X require this conversion for activation and insufficiency causes bleeding
disorders. Deficiency results from fat malabsorption, antibiotic destruction of
K-synthesizing bacteria, the neonatal period, and diffuse liver disease.
D. Water soluble vitamins
1. Thiamine – functions in ATP synthesis, the pentose phosphate pathway, and
neural membrane maintenance. Thiamine deficiency, beriberi, targets the
peripheral nerves, heart and brain. Dry beriberi attacks peripheral nerves
resulting in atrophy. Wet beriberi attacks the heart. Wernicke-Korsakoff
syndrome occurs in chronic alcoholics and is characterized by ataxia,
confusion, and memory loss due to grey matter and mamillary body damage.
2. Riboflavin – is a coenzyme component for redox reactions. It manifests as
cheilosis (skin fissures at the angles of the mouth), glossitis, corneal
vascularization, and suborrheic dermatitis of the face, scrotum, or vulva.
3. Niacin – is a coenzyme component for NAD and NADP required for
metabolic processes. Deficiency results from lack of niacin and tryptophan
(niacin precursor). Manifests as pellagra, characterized by the “three Ds”:
dementia, dermatitis (exposed areas: face, neck, hands and feet), and diarrhea.
4. Vitamin B6 (pyridoxine) – is a coenzyme in metabolic reactions involving
lipids, amino acids, and the immune response. Deficiency may develop with
increased demand in pregnancy or hyperthyroidism, in alcoholics due to
degredation, and with use of antagonistic drugs (isoniazid, estrogens, and
penicillamine). Manifests as seborrheic dermaititis, cheilosis, glossitis,
peripheral neuropathy, convulsions, anemia, and diminished immune function.
5. Pteroylmonoglutamic acid (folic acid)[folate] – is an essential cofactor for
nucleic acid synthesis. Can be depleted in cooked and processed foods.
Pregnant women, alcoholics, embryos, and methotexate patients are at the
greatest risk. Manifests as megaloblastic anemia, neurologic damage, and
filiform papillary atrophy of the tongue, gingival inflammation, and stomatitis.
6. Vitamin B12 (cobalamin) – is important in nucleic acid synthesis.
Absorption is dependant on intrinsic factor (IF). Vegans, post-gastrectomy
patients, the elderly and HIV patients are at the greatest risk. Manifests as
megaloblastic anemia, neurologic damage, dementia, and infertility.
7. Vitamin C (ascorbic acid) – is a cofactor for hydroxylation and an
antioxidant. Vitamin C deficiency, scurvy, is characterized by bone disease in
children and hemorrhages and healing defects in both adults and children.
Wound healing and hemorrhage are due to impaired collagen synthesis.
E. Minerals
1. Iron – serves to transport oxygen in hemoglobin. Impaired absorption,
increased requirement, and chronic blood loss put a person at risk. It is the
most common deficiency, manifesting as hypochromic microcytic anemia,
reversible impaired cognative function, decreased bacteriocidal activity of
neutrophils, reduced cell-mediated immune function, reduced endurance, and
abnormalities in thermoregulation.
F. Trace elements
1. Zinc – is a component of >200 metalloenzymes. Populations at risk are
growing children, patients with high volume diarrhea, and those with high
output GI fistulas. Manifests as acrodermatitis enterpathica of the eyes, nose,
mouth, anus, and distal limbs, anorexia with diarrhea, growth retardation, poor
wound healing, hypogonadism, altered immune function, impaired night
vision, depressed mental function, and increased congenital malformations.
2. Iodine – hypothyroidism – is an essential element of thyroid hormones.
Manifests as hypothyroidism, goiter, impaired mental function, retarded
physical development, abortions, stillbirths, and congenital abnormalities.
2) Describe pathological tissue alterations related to common nutrient deficiencies
using appropriate medical terminology.
Liver – enlarged and fatty in kwashiorkor.
Small intestine – decreased mitotic index of the crypts of the glands in kwashiorkor
associated with mucosal atrophy, loss of villi, and loss of digestive enzymes.
Bone marrow – erythropoietic cells are decreased in kwashiorkor and marasmus
resulting in hypochromic microcytic anemia.
Bone – derangements occur in both rickets and osteomalacia resulting in excess
unmineralized matrix deposition, thinning of bone, and buckling.
PNS – degeneration of axons in the posterior columns of the spinal cord, with focal
accumulation of lipopigment and loss of nerve cells in the dorsal root ganglia (vit E).
CNS – dementia can result from degeneration of neurons in the brain due to niacin
deficiency. Cerebral atrophy can result from protein-energy malnutrition.
Skin – many changes can occur with riboflavin deficiency. Cheilosis fissures
radiating from the corners of the mouth. Glossitis results in an atrophic cyanotic
tongue. Keratitis can result in corneal opacities. Scaly, greasy dermatitis can occur
over the nasolabial folds and also on the vulvar and scrotal regions. Pellagra results
from niacin deficiency and presents as dermatitis on exposed areas.
GI – diarrhea can be caused by niacin deficiency, which results in atrophy of the
columnar epithelium of the mucosa.
3) List three nutrition-related clinical conditions likely to be seen in normative
clinical practice and define the likely categories of patients that will manifest
these disorders.
A. Vitamin B1 (thiamine) deficiency – usually associated with alcoholism
(Wernicke-Korsakoff syndrome) and fad diets.
B. Vitamin C deficiency – those at risk include smokers, young children and the
elderly due to restrictive diets.
C. Iron deficiency – occurs with gastrointestinal blood loss in men and
postmenopausal women.