Calcium Supplementation in Postmenopausal Women Sarah Gilfillan Pharm

Calcium Supplementation in Postmenopausal Women Sarah Gilfillan, Pharm. D sarahegil@gmail. com Kelly L. Scolaro, Pharm. D kelly_scolaro@unc. edu

Objectives After the lecture, students will be able to: Assess a patient’s dietary intake of calcium Understand when to recommend Calcium citrate over Calcium Carbonate Appropriately counsel a post-menopausal women on recommended calcium intake from diet and supplementation

Increased Calcium requirements due to…. Low estrogen levels Increase in bone resorption Decrease in GI absorption efficiency Decrease in renal conservation

Recommendations for Women > 50 years old Elemental Calcium > 1200 mg/day Vitamin D: 800 – 1000 IU/day 25(OH)D level > 30 ng/m. L Include calcium and vitamin D in addition to pharmacotherapy (ex. Bisphonates)

How much is too much? Calcium intake > 2500 mg/day may increase risk of hypercalcemia and renal impairment Impair absorption of other minerals (iron, zinc, magnesium, phosphorus)

Dietary Sources Food Milk Low fat yogurt Collard greens Calcium 300 mg 400 mg 300 mg Soy milk Calcium-fortified Cereal Calcium-fortified Fruit Juice Breakfast bars 80 -300 mg Up to 1000 mg 200 -300 mg 200 -500 mg • Assess dietary intake before supplementing with calcium • Food is the preferred source because often contains other important nutrients

Calcium-Fortified Beverages Information about bioavailability is not on the label Calcium absorption is not the same as milk In tests, the calcium in soy beverages separated into particulate form (80 -90%) Orange juice performed better at 8 -50% Only 11% of calcium in cow’s milk separates out

What to consider when choosing a product Bioavailability Use of antacids Number of tablets needed for desired dose Size of the tablets Cost

Types of Calcium Supplements Salt Carbonate Citrate Phosphate Lactate Gluconate % of elemental Calcium 40% 21% 23 -29% 18% 9% Solubility Insoluble Soluble

Comparison CARBONATE CITRATE Most common Least expensive Relatively insoluble at high gastric p. H Must enter solution to be absorbed Well absorbed when taken with meals More expensive (more tablets) Recommended for: Use with H 2 Blockers or PPIs Calcium supplement w/o meal

Coral Calcium from Okinawa, Japan Became popular due to infomercials claiming health benefits due to high concentration in water Treat or cure cancer, multiple sclerosis, etc Is simply calcium carbonate In 2003 a study showed the health of the Okinawans was due to lifestyle Coral Calcium products may contain excess lead

Side effects Constipation Differentiate from lack of fluid or fiber in diet Gas Bloating

Drug Interactions Levothyroxine Separate by 4 hours Tetracyclines and Quinolones Take 2 hours before or 4 hours after calcium

Why 500 mg at a time? Absorption increases from 200 mg to 500 mg, but does not continue to increase after that No additional benefit of 1000 mg at a time compared to 500 mg

Calcium Combinations

Vitamin D Requirements increase with age Decreased synthesis in the skin Decreased renal conversion to active form Intestine less responsive to its effects Recommendation for adults > 50 800 -1000 IU/day

Sun Exposure 5 – 15 minutes on arms and legs between 10 am and 3 pm 2 -3 times per week For fair-skinned individuals Darker skin tones need 5 t 0 10 times longer exposure Wearing SPF 8 or more reduces ability to produce vitamin D by 95% Lots of research and controversy in this area right now

Types of Vitamin D D 2 (ergocalciferol) Brand: Drisdol ▪ OTC liquid drops ▪ Rx capsules: 50, 000 IU D 3 (cholescalciferol) Multiple strengths and brands OTC Better at raising and maintaining vitamin D levels Rocaltrol (calcitriol) Active form of Vitamin D Only Rx Recommended in advanced renal disease

Vitamin K Becoming more popular for bone health Possibly promotes bone formation and reduces calcium excretion Warfarin patients: Do not have to avoid as long as taking the supplement consistently Monitor INR when stop or start Ex. Viactiv

Magnesium Deficiency may increase activity of osteoclasts Does not improve calcium absorption Laxative effect may help with constipation associated with calcium supplements

Men and Calcium Recent studies suggest NO association with total or non-advanced prostate cancer But, higher risk of advanced and fatal prostate cancer Possible mechanism High calcium levels suppresses vitamin D synthesis Vitamin D may protect against prostate cancer No supplementation recommended for men with calcium-rich diet

Practical Application Average 300 mg/day from diet (non-dairy 300 mg sources) 2 servings of dairy or high-calcium foods 600 mg Calcium supplement or 3 rd serving of dairy 300 mg Daily Total 1200 mg

USP Verified Dietary Supplements http: //www. usp. org/USPVerified/dietary. Supplements/

Questions?