Metabolic and Nutritional Deficiencies

Question 1

Obesity

Answer 1

Background

• chronic disease that leads to variety of medical conditions, ass. w/ various CAs and pre-mature death
• Restrictive bariatric surgery such as “gastric banding” and “sleeve gastrectomy” can be ass w/ deficiencies related to B-vitamins
• iron, folate, vit B1, B12 and D deficiencies ass. w/ malabsorptive procedures “biliopancreatic diversion,” “duodenal switch” and “Roux-en-Y gastric bypass”
• defined by BMI  25-29.9 = overweight, >30 = obese
• associated medical conditions = T2DM, HTN, OSA, prostate CA, GERD, non-alcoholic steatohepatitis

Mgmt
-diet and exercise  can lose avg of 10-20lbs alone
-pharmacotherapy
-bariatric surgery  most effective tx for severe obesity, substantial/sustained wgt loss, resolution of medical conditions
-surgery ind for BMI >40 or BMI >35 w/ obesity-related condit
-neurohormonal mechanisms  GLP-1, PPY, Ghrelin, leptin
surgical options  Lap gastric band, Roux-en-Y gastric bypass, sleeve gastrectomy

Question 2

Vitamin A deficiency

Answer 2

• visual changes (night blindness)
• impaired immunity, dry skin, poor bone growth, taste loss
• squamous metaplasia (white Bitot’s spots on conjunctiva)
• fxn  vision, immune, embryo dev, hematopoiesis, skin/cell health
• RF  pt w/ liver dz, alcoholics, fat free diets
• fat soluble, absorbed in duodenum  disturbed by bypass surgery

Question 3

Vitamin C deficiency (Ascorbic acid)

Answer 3

• RF  diets lacking raw citrus fruit and green veg, smoking, ETOH, malnourished, elderly
• absorbed in small bowel

-scurvy  hyperkeratosis, hemorrhage (gums, joints), hematologic

Question 4

Vitamin D deficiency

Answer 4

• from fortified milk and sun exposure
• fat soluble, absorbed in duodenum and ileum
• rickets (children)  softening of bones leading to bowing deformities and fx
• osteomalacia  diffuse body pain, muscle weakness, fx
• looser lines (radiolucencies on X-ray)
• ergocalciferol (Vit D)

Question 5

Vitamin B1 deficiency

Answer 5

• thiamine is coenzyme for carbohydrate metabolism  absence drives carb metab toward lactic acid
• structural component of nerve membranes for nerve conduction  deficiency affects CNS
• deficiency can occur in 14 days of inadequate intake d/t short half life
• ETOH m/c cause in US
• eyes  nystagmus
• nervous sys dry beriberi (paresthesia, weak LE), Wernicke’s encephalopathy (AMS, confusion, nystagmus, gait ataxia), Wenicke-Korsakoff syndrome (psychosis, memory)
• wet beriberi (high-output HF, dyspnea), sodium/water retention, lactic acidosis

-5-1500 mg thiamine daily (IV > PO for alcoholic pt at risk for refeeding or in ICU)

thiamine supplement is only effective if Mg2+ is replete  Mg2+ converts thiamine to its active form

Question 6

Vitamin B2 deficiency

Answer 6

Riboflavin

• oral-oculo-genital syndrome
• oral  lesions of mouth, magenta colored tongue, angular cheilitis, pharyngitis
• ocular  photophobia, corneal lesions
• genital  scrotal dermatitis

Question 7

Vitamin B3 deficiency

Answer 7

Niacin

• often d/t diets high in corn or diets which lack tryptophan
• Pellagra (3Ds)  diarrhea, dermatitis, dementia

Question 8

Vitamin B6 deficiency

Answer 8

Pyridoxin

-etiologies  chronic alcoholism, isoniazid, OCPs

• periph neuropathy, seizure, HA
• stomatitis, cheilosis, glossitis, flaky skin, anemia

Question 9

Vitamin B12 deficiency

Answer 9

Cobalamin

• animal food primary source
• stomach acids release B12 from food, binds it to intrinsic factor for later absorp in terminal ileum
• etiologies  pernicious anemia (AI destruction of gastric parietal cells that secrete IF), strict vegans, malabsorption (ETOHism, dz affecting ileum like Celiac or Crohns),  intrinsic factor production (PPIs)
• neuro  paresthesia, gait abnormalities, memory loss, dementia
• GI  anorexia, diarrhea, glossitis
• CBC = Macrocytic anemia (MCV) w/ hypersegmented neutrophils
• pernicious anemia  ab testing, Schilling test

-intramuscular or oral B12

Question 10

Refeeding syndrome

Answer 10

• reintroduct of glucose causes  in insulin secretion  cellular uptake of glucose, phosphorus, Mg2+, K+   need for thiamine cofactor for carb metabolism
• lasts up to 72 hours
• RF  malnutrition, hx of wgt loss, prolonged fasting, malabsorption, long term diuretic use, morbidly obese w/ profound wgt loss
• classic pts  anorexia nervosa, chronic alcoholism, oncology pt, post-op patients, prolonged emesis, NPO >7 days, uncontrolled DM
• cardiac, pulmonary, and neuro sx d/t hypokalemia, hypophos, hypoMg2+, and thiamine def

-check BMP, Mg2+, and phos 1-3 times/day

• supplement electrolytes before and during refeeding
• start multivitamin
• supplement thiamine
• start low and go slow w/ calories