Vitamin Supplementation Flashcards
Water soluble vitamins
B1, B2, B3, B6, B12, folate/B9, C
Fat soluble vitamins
A, D, E, K
Energy-releasing vitamins
B1 (thiamine), B2 (riboflavin), B3 (niacin)
Hematopoiesis vitamins
B6 (pyridoxine), B12 (cyanocobalamin), B9 (folate)
Physiologic role of B1/thiamine
Coenzyme in the intermediary metabolism of multiple essential reactions
Physiologic role of B2/riboflavin
Plays a role in numerous respiratory systems
Physiologic role of B3/niacin
Component of two coenzymes
Physiologic role of B6/pyridoxine
Coenzyme in amino acid metabolism
Physiologic role of B12/cyanocobalamin
B12 coenzymes are essential for cell growth and replication
Physiologic role of B9/folic acid
DNA synthesis and hematopoiesis
Physiologic role of Vitamin C/ascorbic acid
Cofactor for electron transfer to enzymes, required for collagen synthesis and wound healing
Physiologic role of vitamin A
Essential in retinal function, growth and differentiation of epithelial tissue, enhances immune function, bone growth, reproduction, embryonic development
Physiologic role of vitamin E
Antioxidant
Physiologic role of vitamin D
Synthesized from cholesterol upon exposure to UVB; functions in the body as a steroid hormone
Recommended dietary allowance (RDA) definition
Average daily level of intake sufficient to meet the nutrient requirements of nearly all healthy individuals
Adequate intake (AI) definition
Established when evidence is insufficient to develop on RDA; intake of this level is assumed to ensure nutritional adequacy
Estimated average requirement (EAR) definition
Average daily level of intake estimated to meet the requirements of 50% of healthy individuals
Tolerable upper intake level (UL) definition
Maximum daily intake unlikely to cause adverse health effects
B1 deficiency is likely to happen in what population?
Alcoholics
Complications of B1 deficiency
Wernicke’s Encephalopathy, Korsakoff’s Psychosis
Symptoms of Wernicke’s Encephalopathy
Confusion, nystagmus, ataxia
Treatment for Wernicke’s Encephalopathy
50-100mg IV thiamine
How does Korsakoff’s Psychosis develop and what are the symptoms?
If Wernicke’s Encephalopathy is untreated, it can develop to Korsakoff’s Psychosis, a chronic state of irreversible damage and cognitive impairment
Symptoms of B2 deficiency
Glossitis, cheilosis, dermatitis, corneal vascularization, cataracts, anemia
Symptoms of B3 deficiency
Pellagra: diarrhea, dementia, dermatitis
B6 INH treatment
15-30mg/day for patients predisposed to neurotoxicity, 50-200mg/day in established neuropathy
DDIs with B6: levodopa
Enhances peripheral decarboxylation
DDIs with B6: phenobarbital, phenytoin
Decreased SDCs
B12 deficiency is likely to happen in what age group?
> 50 years old
Complications of B12 deficiency
Macrocytic anemia, irreversible nervous system damage
B12 DDIs
Possible DDIs with metformin, PPIs, H2RAs
Cause of folic acid deficiency
Drug therapy may induce it and alcoholism impairs enterohepatic recycling of folic acid
Folic acid deficiency DDI: methotrexate and trimethoprim
Inhibits DHFR
Folic acid deficiency DDI: phenytoin and oral contraceptives
Impairs storage
Vitamin C deficiency leads to what condition?
Scurvy
Signs and symptoms of scurvy
Defect in collagen synthesis, failure in wound healing, defects in tooth formation, gingivitis
Scurvy is seen in what populations?
Elderly, alcoholics, drug addicts, patients with inadequate diets
Vitamin A deficiency consequences
Involve all epithelium, can lead to blindness and hypervitaminosis A with excessive intake
Vitamin E deficiency consequences
There’s no unequivocal evidence that exists to show that vitamin E is even necessary for humans to take
Factors that go into Vitamin D deficiency
Age, skin color, geography, sun exposure
Benefits of taking Vitamin D
Helps with:
General health and deficiency, CVD risk, diabetes, respiratory diseases, eye diseases, infectious diseases, neurologic disease, colon and breast cancer
Vitamin D toxicity
Hypercalcemia from consuming >10,000 units/day
Vitamin D toxicity symptoms
Anorexia, diarrhea, constipation, vague aches, depression, hallucinations, amnesia, impaired renal function, widespread tissue calcification, decline in growth rate in children, death
Vitamin D toxicity treatment
Withdraw vitamin, administer fluids, very low calcium diet
Vitamin D levels for deficiency
<30 nmol/ml, 12 ng/ml
Vitamin D levels for inadequate intake
30-50 nmol/ml, 12-20 ng/ml
Vitamin D levels for adequate intake
≥50 nmol/ml, ≥20 ng/ml
Vitamin D levels that cause adverse effects
> 125 nmol/ml, >50 ng/ml
Best indicator of immediate vitamin D status
Cholecalciferol (D3 levels); half-life is one day and represents day-to-day exposure
Best indicator of vitamin D exposure
Calcidiol (25(OH)D) levels; half-life is 15 DAYS and represents vitamin D produced by the skin and consumed over a longer period
Worst indicator of vitamin D status
Calcitriol (1,25(OH)2D) levels; half-life is 15 HOURS and levels don’t decrease until deficiency is severe
Vitamin D replacement
Expected change in blood concentration of calcidiol with daily dosing for 2-3 months; then use maintenance doses once level is achieved
Which form of vitamin D is more efficient? (D3 or D2)
D3
Intermittent vs. daily dosing of Vitamin D
The PK of vitamin D allows for intermittent high doses but increases fall risk in the elderly and increased risk and duration of URIs
Patient factors that contribute to increased vitamin requirements
Weight reduction and fad diets Malabsorptive states/bariatric surgery Pregnancy Alcohol consumption Drug-nutrient interactions Osteodystrophy Elderly Refugees/immigrants
Recommendations for patients where supplementation is beneficial: deficiency, “at risk”
Malnutrition, age, DDIs, malabsorption
What vitamins to use if a patient is taking metformin or a PPI
B12, calcium, magnesium
Recommendations for patients where supplementation is beneficial: maintaining bone health
Take vitamin D per DRI in conjunction with calcium (get at least 50% of calcium from diet)
Recommendations for patients where supplementation is beneficial: pregnancy
FOLIC ACID! Iron if anemic
Recommendations for patients where supplementation is beneficial: macular degeneration
Antioxidant/mineral combination products
Cancer and CV protection and prevention: what would increase harm to these patients?
High dose supplements of beta-carotene, vitamin E, selenium, vitamin C, and folic acid aren’t recommended
Increased harm of Vitamin E
Excessive bleeding with higher doses in conjunction with anticoagulant therapy
Increased harm of Vitamin A
Smokers have increased mortality
Primary literature: Vitamin D and CVD risk
Higher concentrations of Vitamin D, lower risk of CVD
Primary literature: Vitamin D intake in invasive cancer and CVD events
No difference between the placebo and Vitamin D treatment group
Primary literature: vitamin intake in healthy adults without special nutritional needs for primary prevention of CVD and cancer
No recommendations for multivitamins, single-or-paired nutrient supplements, beta-carotene, or vitamin E
Primary literature: there is an increased risk of mortality in patients taking what vitamins?
Beta-carotene/Vitamin A, Vitamin E
Primary literature: what shouldn’t be used in women <65 for CVD prevention
Menopausal therapy, antioxidant supplements, folic acid, and ASA
Where are AREDS supplements used?
Age-related macular degeneration
Which formulation of AREDS can you use in smokers? (AREDS or AREDS-2)
AREDS-2! Doesn’t contain beta-carotene