12 things you need to know about calcium supplements for bone health

Posted on: September 4th, 2014 by Dr. Richard R. Olson

[quote]High priced “brand name” Calcium tablets offer no advantages, in spite of their marketing claims.[/quote]

1. Why is Calcium important?

Calcium plays a critical role in proper function throughout the body, including blood cells, muscle, and nerve.  Over 98% of the Calcium in our body is in bone tissues, where it provides strength.  For proper function, the body keeps blood Calcium levels within a narrow range.  We lose a small amount of Calcium each day through skin, hair, nails, urine, and feces.  When dietary Calcium intake is not adequate to replace this, Calcium is taken from bone. People with inadequate Calcium intake lose bone at a faster rate and have a greater chance of developing weak, fragile bones (Osteoporosis).

2. How much Calcium do I need?

Experts generally agree that a total of 1000-1200 mg of elemental Calcium per day is enough for adults.  This includes the Calcium in your diet plus any Calcium from supplements.

3. Does everyone need to take Calcium supplements?

No.  If you get enough calcium from the foods you eat, then you don’t need to take a supplement.  Calcium supplements are only necessary if dietary intake is too low.  In the USA, average dietary Calcium intake is around 600 mg per day.  Changes in diet or addition of supplements are the two options to make up any shortfall.

4. How much Calcium is in my diet?

Most people obtain about 250 mg per day from food, plus an additional 200-300 mg per serving of dairy products (glass of milk, cup of yogurt, or an ounce of cheese).  Check food labels- when they refer to % daily value (%DV), that is based on a daily intake of 1000 mg.  (20% DV=200 mg, 30%DV=300 mg, etc.)

5. Is there one Calcium supplement that is best?

Choose a Calcium tablet labeled USP (United States Pharmacopeia). This indicates it passed tests for dissolving completely within the intestinal tract. There are only minor differences in absorption between Calcium Citrate and Carbonate.  Patients that have difficulty swallowing pills may consider one of the chewable Calcium options.

6. Are the more expensive Calcium supplements better and are liquids preferable?

No. Generic Calcium supplements are fine.  High priced “brand name” Calcium tablets offer no advantages, in spite of their marketing claims.  Liquid preparations are not necessary.  Calcium from tablets is absorbed very well- as well as Calcium from dairy products, and better than many food sources such as spinach.

7. How much Calcium is in a Calcium supplement?

The amount of Calcium per tablet is listed under ingredients, and generally ranges between 200 and 600 mg per tablet.  Note that the label states the amount of Calcium per serving, and the serving size sometimes may be two or more tablets.  Does a 600 mg Calcium seem bigger and harder to swallow compared to medications of similar dose? That is because the total tablet size is indeed much larger.  For Calcium Carbonate, 40% is Calcium and the other 60% is Carbonate.  A 1500 mg tablet contains 600 mg Calcium and 900 mg Carbonate.

8. Should I take all Calcium supplements at once, or spread out the doses?

Spread them out.  For example, take one Calcium pill twice a day, rather than two Calcium tablets at once.  The intestinal tract absorbs Calcium more efficiently when it is spread throughout the day.  Taking Calcium supplements with food also improves absorption.

9. Do Calcium supplements have side effects?

Intestinal bloating, gas, and constipation can occur occasionally, especially at higher doses.  Calcium Citrate has a lower risk of intestinal bloating and gas compared to Calcium Carbonate.

These problems are minimized by using a low starting dose and increasing gradually. Avoiding higher than necessary doses is also helpful.

10. Is it possible to take too much Calcium?

Yes.  Calcium intake over 2000 mg per day does not provide any additional benefit to your bones and it will increase your risk of kidney stones and gastrointestinal side effects.

11. If I take enough Calcium and Vitamin D, can I stop or avoid taking Osteoporosis medications?

No.  Calcium and Vitamin D intake are very important, but they do not take the place of prescription medications in patients with high fracture risk.

12. If I start taking a medication for Osteoporosis, do I need to continue taking Calcium and Vitamin D?

Yes.  Osteoporosis medications have been shown to lower fracture risk only in patients who are receiving adequate amounts of Calcium and Vitamin D.