12 - Common Vitamins & Minerals Flashcards
Which calcium has the highest percentage of elemental calcium?
Calcium carbonate
For optimal absorption, calcium doses should not exceed ___ mg of elemental calcium
500
What should be done if more than 500 mg of calcium supplementation is needed?
Divide it throughout the day (BID or TID)
Where does the best calcium absorption occur?
Acidic environment, so should be taken w/ meals
What should calcium supplements not be taken w/?
High fiber meals and foods like spinach, nuts, beans, seeds, and wheat bran b/c may decrease absorption
Which type of calcium is first line?
Calcium carbonate
What is a potential side effect of calcium supplements?
Constipation, so fiber can help this, just don’t consume fiber and calcium together
When is calcium citrate recommended?
Px on PPI’s or H2 blockers, inflammatory bowel disease, or absorption disorders
Does calcium citrate need to be taken w/ food?
No, can be taken on an empty stomach
What is an advantage to calcium citrate over calcium carbonate?
Calcium citrate has increased absorption, especially in px w/ high gastric pH
Are natural preparations of calcium from oyster shells or bone meal safe?
May contain lead, but calcium blocks lead absorption
What are some consequences of calcium overdose?
- Kidney stones
- Milk-alkali syndrome
- Renal insufficiency
Iron supplements containing more than ___ mg of elemental iron are schedule 2
30 mg
Which type of iron is more readily absorbed?
Ferrous iron (not ferric)
Where does majority of iron absorption occur?
Distal duodenum and proximal jejunum
Are enteric coated or sustained release iron supplements effective?
Not if iron is released past the duodenum or jejunum
Where is excess iron stored and what can this lead to?
- Tissues and organs
- Cirrhosis, heart failure
What are the different formulations of iron from least to most elemental iron?
- Least = ferrous gluconate
- Ferrous sulfate
- Ferrous fumarate
Should iron salts be taken w/ food or on an empty stomach?
Empty stomach
Which foods can impair iron absorption?
- Cereals
- Dietary fiber
- Tea, coffee
- Eggs
- Milk
What can be done if iron salts cause stomach irritation?
- Take w/ food
- Switch to product w/ less elemental iron
- Smaller, less frequent doses
- Switch to liquid formulation for smaller titrations (however not very palatable)
Which medications can decrease absorption of iron?
- Antacids, PPI’s, H2 blockers
- Take iron 2 hours before or 4 hours after antacids
What can be done if px on PPI’s need iron supplementation?
- Changing timing of dosing won’t help
- Want to choose a product that won’t interact or doesn’t require acid
What are some GI side effects of iron?
- Abdominal discomfort
- N/V
- Diarrhea, constipation
- Dark stools
What effect does vitamin C have on iron absorption?
Increases iron absorption
What effect do B vitamins have on energy?
Help to release energy from food
What should be done if a px asks for a B vitamin to relieve stress?
- Suggest non-pharms
- Reduce caffeine, alcohol, and smoking
- Exercise
- Sufficient sleep
- Relaxation techniques
Do B vitamins decrease risk of skin cancer?
- No effect in px w/o skin cancer, so not a replacement for current recommendations for sun protection
- Niacinamide was shown to help high-risk px who already have nonmelanoma skin cancer
What is the leading cause of poor vision in adults over 60 y/o and of adult blindness?
Age-related macular degeneration
What is macular degeneration?
- Deterioration of macula
- Macula is small area at center of retina in the back of the eye, purpose is to permit seeing fine details clearly
- Loss of central vision yet peripheral vision unaffected
What are some non-modifiable risk factors for age-related macular degeneration?
- Older age (usually over 50 y/o)
- Ethnicity (caucasian and asian)
- Genetics
What are some modifiable risk factors for age-related macular degeneration?
- History of smoking
- Obesity
- Diet w/ high saturated fat
- Diet w/ low omega-3 fatty acids
- Diet w/ low antioxidants and zinc
What are signs and symptoms of age-related macular degeneration?
- Blurred center of vision
- Vision impairment
- Dark adaptation decreased
- Vision distortion (straight lines look wavy)
- Blank areas in vision / partial loss of vision
- Flashes of light
What is dry age-related macular degeneration?
- Result of thinning of macula
- More common form
- Development occurs over many years
- 3 stages – early, intermediate, and advanced
What is wet age-related macular degeneration?
- Result of abnormal blood vessels growing under retina
- Less common, but more serious
- Quickly progresses, leading to severe vision loss or blindness
What is the tx for wet AMD?
- Anti-vascular endothelial growth factor injections
- Photodynamic therapy
What is the tx for dry AMD?
- No proven effective tx
- Current recommendation for px w/ intermediate to advanced stages of dry AMD is AREDS2 formulation (vitamin A, C, lutein, and zeaxanthin) to reduce further progression
Potential nutrient depletion caused by Orlistat
- May be a decrease in levels of some fat soluble vitamins and beta-carotene
- Recommended for px to take multivitamin supplement at least 2 hours before/after Orlistat
Potential nutrient depletion caused by metformin
- Decrease in folate and vitamin B12 in some px
- Monitor vitamin B12 yearly
- Some px may require supplements
Potential nutrient depletion caused by corticosteroids
- Oral corticosteroids w/ high mineralocorticoid activity can cause steroid-induced osteoporosis
- Supplements w/ calcium and vitamin D needed in px taking > 7.5 mg prednisone daily (or equivalent)
Which oral corticosteroids have high mineralocorticoid activity?
- Hydrocortisone
- Cortisone
- Prednisone
- Prednisolone
Which drugs does vitamin A (beta-carotene) interact w/?
- Retinoids (avoid combination)
- Hepatoxic medications, acetaminophen, carbamazepine, methotrexate (avoid combination)
- Warfarin (avoid combination)
What drugs does vitamin E interact w/ and what should be done for management?
- When combinated w/ warfarin, ASA, or NSAIDs may increase risk of bleeding
- Restrict vitamin E to less than 200 IU per day and monitor INR for warfarin
