Fluid And Electrolyte Absorption Flashcards
Vitamins
Catalysts (cofactors) and substrates
Coenzymes: carry chemical groups between enzymes
Fat soluble vitamins: ADEK
Vitamin B12
Cobalamin
Attached to food proteins
Pepsin and stomach acidity release B12
Gastric glands secrete transcobalamin and binds B12 with high affinity
Parietal cells produce intrinsic factor with low affinity
B12 deficiency
Neuropsychiatric symptoms precede hematologic signs
Fatigue, depression, poor memory
Mania and psychosis
Vitamin A
Night blindness
Hyperkeratosis
Keratomalacia
Retinol, retinal
Vitamin D
Rickets
Osteomalacia
Fish, eggs
Vitamin E
Deficiency rare
Sterility in males, abortions in females, mild hemolytic anemia in newborns
Fruits and vegetables, nuts and seeds
Vitamin K
Bleeding disorders
Leafy greens, synthesized by colonic bacteria
Carboxylase cofactor in production of coagulation proteins
K1: plants, K2: intestinal flora, K3: synthetic, water soluble used for treating deficiencies
Bacteroides
Gram negative bacillus
Normally mutualistic
Play fundamental role in processing of complex molecules to simpler ones in host intestine
Large intestine absorbs vitamins created by bacteria (esp vitamin K)
Minerals
More than 100mg needed per day
Ca: bone and teeth, membrane stability, cell signaling
Transcellular uptake in duodenum, paracellular throughout SI
Mg: cofactor in metabolism
P: bone and teeth, energy bonds
Na: membrane excitability
K: membrane excitability
S: aa component (cysteine), disulfide bonds strengthen keratin
Cl: cell excitability
Trace elements
< 100mg/day Fe: resp pigments Iodine: thyroid hormone synthesis Chromium: aids glucose uptake Cu: enzyme cofactor, collagen Manganese: cholesterol synthesis Molybdenum: protein anabolism Zinc: enzyme cofactor Boron: alters mineral metabolism, enhances estrogen in post-menopausal women
