Calcium Stealers: Medications and Substances That Impede the Absorption of Calcium

Pam Flores Health Guide February 06, 2010
  • It's so important to get the proper amount of calcium to fight bone loss and other medical disorders; so make sure you are checking what you eat to be sure you aren't consuming something that hinders calcium's affect.


    Do you know what medications or foods sabotage your daily intake of this vital nutrient?


    How ever you get your calcium, whether from food or supplements, we must be aware that there are things that can interfere with our hard work by depleting or blocking the calcium we consume.


    Substances That Interfere with Calcium Absorption:

    • Oxalates reduce calcium absorption (examples of foods high in oxalate are: spinach, rhubarb and beet greens)
    • Phytate Sodium (example of a foods high in phytate are: 100% wheat bran, pinto beans, navy beans and peas). You can reduce the phytate level in beans or legumes by soaking them in water for several hours, discarding the water, and then cooking them in fresh water.  If you eat wheat bran, take your calcium 2-4 hours before or after eating 100% wheat bran.
    • Protein (Our daily calcium requirement increases with diets too high in animal protein)
    • Caffeine (Excess caffeine interferes with calcium absorption)  You can counteract excess caffeine by adding milk to your drink, or extra calcium to your routine of drinking caffeinated beverages.
    • Sodium (Excess sodium inhibits calcium absorption)
    • Vitamin D deficiency (inhibits calcium absorption)

    Calcium Interactions:

    • Tetracycline (calcium may reduce absorption of this antibiotic)
    • Iron Supplements (calcium should not be taken at the same time as iron)
    • Thyroid hormones (take calcium 4 hours apart from thyroid hormones)
    • Medications taken on an empty stomach (these medications should not be taken at the same time as calcium) 
    • Proton Pump Inhibitors (such as Prevacid®, Prilosec®, and Nexium® interact with calcium).  Because these medications block stomach acid, you may better absorb these with calcium citrate which does not need stomach acid for absorption.

    It's best to get our calcium, whether from diet or supplements, in doses of no more than 500 - 600 milligrams per serving, or less, taken several times a day.  If you get the required dose for calcium from your food (1,200 mgs for those over 50, and 1,000 mgs for those under 50) then you wouldn't need to supplement with additional calcium tablets.  Check your total daily intake through foods and drinks and then decide if you need to add more calcium to that to equal the Recommended Daily Allowance (RDA) of 1,200 mgs.


    I hope you are getting what you need from your calcium; and be sure to check this list for things that could hinder your hard work in getting the proper amount of calcium.


    List Source: National Osteoporosis Foundation (NOF) 2010 on Calcium.

    Other Resources on Supplements From HealthCentral:  Getting the Most From Your Vitamin D

    Medications That Cause Bone Loss   Calculating How Much D You Get From the Sun