Wednesday, 3:00 – 4:30, F6
The Myths and Truths of Vitamin D
Teresa Bailey, PharmD
[email protected]
Objectives:
Identify advances in clinical assessment and management of selected healthcare issues related to
persons with developmental disabilities
Notes:
Vitamin D (antirachitic vitamin)
 Rickets was first identified in 1650 but it took 270
yrs. before researchers identified the fat-soluble
substance in cod liver to cure the disease
 Only vitamin that the body can synthesize
Teresa M. Bailey, PharmD, BCPS, BCACP, FCCP
Professor, Clinical Pharmacy
Ferris State University College of Pharmacy
 10 different compounds
 D1,D2,D3 etc.
 D2 ergocalciferol derived from plants
 D3 cholecalciferol derived from animal

Is Vitamin D2 or D3 Better?
is manufactured by the body
Is Vitamin D2 or D3 Better?
 D3 is the most natural form since humans make it
 Humans can not make D2
 D3 is more potent
 At nutritional doses vitamins D2 and D3 are equivalent,
but at high doses vitamin D2 is less potent
 D3 greater absorption
 D3 may be less toxic
 D3 has been the form most studied
 D3 has a more stable shelf life
 D3 has a longer half-life
Is Vitamin D2 or D3 Better?
 Mushrooms contain D2. Otherwise all other foods
So why is Vitamin D2 still
prescribed?
contain D3
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So why is Vitamin D2 still
prescribed?
 D2 was first discovered in 1920s and marketed
 1949 World Health Organization declared differences
were “minimal”
Sunlight
Sunlight
 How much sunlight is required to get your daily
 21 year old man or woman exposed to summer UVB
vitamin D????
light generates 10,000 IU of Vitamin D in 15-20
minutes
 Equal to:
 25 tablets of 400 IU Vitamin D tablets
 10 tablets of 1,000 IU Vitamin D tablets
 100 glasses of milk
 Longer exposure has no benefit
Vitamin D
Sunfriend wristband
 Vitamin D synthesis decreases with
age
 Levels are only 30% of what you
would see in a healthy young adult
 Becomes more dependent on diet to
provide adequate levels
 T or F
 If you wear sunscreen, your body will
not produce Vitamin D.
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Vitamin D
Vitamin D--Deficiency
 FUNCTIONS:
 Osteoporosis:
 Regulates calcium and phosphorus in intra/extra cellular
compartments
 Aids in the absorption and metabolism of these
minerals in the intestine and bone
 Regulates calcium deposits (mineralization) and
removal (demineralization)
 Regulates excretion of calcium from the kidneys and
maintains normal blood levels
 Requires optimal intake of vitamin D and calcium
 Osteomalacia:
 Develops in women with closely spaced, multiple
pregnancies
 Patients confined indoors with no exposure to sunlight
 Rickets:
 Poor ossification of bone tissue
 Results in weak, bendable bones, knock-knees, bowed
legs, spinal curvature, disfiguring of the skull
Who is at risk?
RDI
 People who live in smoggy/overcast areas
 600-800 IU/day in healthy adults
 People who live and work primarily indoors
 Seniors may require higher doses
 Questionable
 Dosing range is 800 IU
 25-OH Vitamin D level
 Dark-skinned people
 >50 years old



Normal = 30-75 ng/mL
Insufficient = 20-29
Deficient = < 20
 Usually 2,000-10,000 IU/day
 Cases of 20,000 IU/day
Available Dose/Serving
 Vitamin D2
 50,000 IU capsules
 8,000 IU/ml oral solution
 Vitamin D3
 100 IU, 400 IU, 1,000 IU, 2,000 IU, 5,000 IU, 10,000 IU
and 50,000 IU capsules/tablets
 1,000 IU and 5,000 IU drops
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Toxicity
 No toxic dose has been established
 Excessive intake for long periods of time can cause toxic
levels in the kidney, liver, skeletal muscle and adipose
tissue
 Symptoms range from nausea to mental retardation
 More concern of hypercalcemia due to too much
absorption of calcium
 High levels of calcium in urine = renal stones
 Toxicity symptoms: nausea, vomiting, constipation, and
polyuria
Vitamin D
Vitamin A
 Dietary Sources:
 Fortified
 TOXICITY:




Vitamin D fortified milk (100 IU/cup)
Cereals
Grain products
Yogurt, cottage cheese, butter, cream
 Naturally occurring


Liver, egg yolk
Cod liver and other fish oils
 1 tablespoon of cod liver oil each day
 Equals 400-1,200 IU/day
 BUT contains Vitamin A 4,000-30,000 IU
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Learn why vitamin D is truly a super supplement
 Stored in liver daily, daily supplementation is usually not
necessary
 Toxicity has been reported in adults taking > 25,000 IUs
daily for several years
 Range reported to cause toxicity 18,000-60,000 IU over
months
 Symptoms include:
 Dry itchy skin, bone pain, anorexia, diarrhea, birth defects,
brittle nails, gingivitis, fatigue, increased infections, hair loss,
headaches, enlarged liver, abnormal liver function
 Birth defects: face, head, brain, heart
Cancers
 Epidemiologic studies show incidence and death rates
for cancers were lower among individuals living in
southern latitudes
 Colorectal
 Breast
 Prostate
 Pancreatic
 Kidney
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Cancers
Erectile Dysfunction
 Prostate Cancer
 African American men with low Vitamin D levels more
likely to test positive for prostate cancer
 Men with severe erectile dysfunction had significantly
lower Vitamin D levels compared to men with mild ED
 Breast Cancer
 Animal studies show Vitamin D reduces cell growth and
promotes cell death
 Prospective cohort studies mixed results


May lower risk in premenopausal women
Meta-analysis shows no link
 Randomized controlled trial

No difference with Vitamin D 400 IU day
Stroke
Heart Disease
 Twice the risk of stroke when Vitamin D level below 50
 Vitamin D deficiency is a
 Deaths due to stroke/CV event increased by 33% when
Vitamin D level was above 100
risk factor for heart
disease
 Unknown whether
Vitamin D
supplementation will
decrease the risk
Hsia J, Heiss G, Ren H, et al. Calcium/vitamin
D supplementation and cardiovascular
events. Circ 2007
Parkinson’s Disease
 Randomized, placebo trial
 According to the Parkinson’s Disease Foundation
 36,282 postmenopausal women
 Calcium carbonate 500 mg/Vit D3 200 IU twice daily
 No effect on coronary or cerebrovascular risk over 7
year period
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Schizophrenia
Dementia
 19 observational studies
 Low levels of Vitamin D
 53% increased risk of developing dementia
 70% more likely to develop Alzheimer’s
 Vitamin D deficient twice as likely to be diagnosed
with schizophrenia
 Severely deficient
 125% increased risk of dementia
 120% more likely to develop Alzheimer’s
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Selected Food Sources of Calcium
Recommended Intake for Calcium
Male and Female
Age
Calcium (mg/day)
Pregnancy &
Lactation
0 to 6 months
200
N/A
7 to 12 months
260
N/A
Food
Calcium
(mg)
% DV
Yogurt, plain, low fat, 8 oz.
415
42%
Yogurt, fruit, low fat, 8 oz.
245-384
25%-38%
Sardines, canned in oil, with bones, 3 oz.
324
32%
Cheddar cheese, 1 ½ oz shredded
306
31%
1 to 3 years
700
N/A
Milk, non-fat, 8 fl oz.
302
30%
4 to 8 years
1000
N/A
Milk, reduced fat (2% milk fat), no solids, 8 fl
oz.
297
30%
Milk, whole (3.25% milk fat), 8 fl oz
291
29%
Milk, buttermilk, 8 fl oz.
285
29%
Milk, lactose reduced, 8 fl oz.**
285-302
29-30%
Mozzarella, part skim 1 ½ oz.
275
28%
Tofu, firm, made w/calcium sulfate, ½ cup***
204
20%
Orange juice, calcium fortified, 6 fl oz.
200-260
20-26%
9 to 13 years
1300
N/A
14 to 18 years
1300
1300
19 to 50 years
1000
1000
51+ years
1200
N/A
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Calcium Products
http://ods.od.nih.gov/factsheet
s/Calcium_pf.asp
Calcium Products
 Must be soluble and ionized for absorption
 Acidic pH increases solubility
 Vitamin D also necessary
 Insoluble salts should be taken with food
 Calcium carbonate, phosphates, “shell” products
Calcium Products
http://ods.od.nih.gov/factsheets/Calcium_pf.asp
 Soluble salts offer benefit for patients with
achlorhydria (elderly, those taking H2RAs, PPIs)
 calcium citrate, lactate, or gluconate
 Oyster calcium: ? Iron content (calcium
carbonate)
 Coral calcium:  absorption – little evidence
 2:1 ratio with magnesium (doesn’t  absorption )
Calcium Administration
 Dosage forms should be taken as directed
 Individual doses >500 mg will not be absorbed
 Use BID or TID schedule
 Vitamin D 400-1,000 IU/day advised to ensure
absorption
Safety
 Side effects: gas, bloating, abdominal discomfort
 May be remedied by changing salt form
 Avoid doses >2.0 grams/day (tolerable upper limit)
 High levels of calcium in urine = renal stones
 Toxicity symptoms: nausea, vomiting, constipation, and
polyuria
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Drug Interactions
Drug Interactions
 Drug levels decrease
 Digoxin
 Fluoroquinolones
 Thiazides increase calcium levels

Separate by 2 hrs before or 6 hrs after the antibiotic
 Levothyroxine

Separate by 4 hrs.
 Tetracyclines
 Separate by 2 hrs before or 6 hrs after the antibiotic
 Aluminum and magnesiums antacids increase urinary
calcium excretion
 Separate by 2 hrs
 Mineral oil and stimulant laxatives decrease calcium
absorption
 Glucocorticoids deplete calcium
 Phenytoin, phenobarbital, carbamazepine
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