Bone and Calcium: Video as Researcher Clarifies Concerns

Almost everybody knows that we need calcium for healthy bones.  Beyond that, though, the details often get a little fuzzy when it comes to knowing whether or not you’re getting the right amount.

While I was speaking in New York City recently, I took advantage of the chance to catch up both personally and professionally with my long-time friend from days back in graduate school at Cornell University, Jeri Nieves, PhD.  Dr. Nieves is Associate Professor of Nutrition and Epidemiology at Columbia University and Helen Hayes Hospital, where she is known for research on bone health and osteoporosis. Here is some video from our conversation.

Take-home points from Dr. Nieves
Getting enough calcium is vital for bones, but it is possible to get too much of a good thing.

Latest recommendations on calcium for adults call for 1000 milligrams (mg) daily, increasing to 1200 mg for women after age 50 and for men after age 70.

These calcium recommendations refer to your total from food and supplements.  If you think you aren’t able to meet recommended amounts through food alone, don’t get a supplement that provides the complete recommendation. There is no known benefit to getting calcium beyond that, unless your doctor has specifically advised you to do so.  Adults should not exceed 2500 mg of calcium per day, and after age 50 that safety limit drops to 2000 mg a day.

For vitamin D, from childhood onward aim for 600 International Units (IU) daily; after age 70 increase that to 800 IU daily.  Getting extra calcium does not make up for lack of enough vitamin D, so it is important to make sure you’re getting enough.  Check my recent blog posts about vitamin D’s potential role in reducing cancer risk and about how to make sure you get enough vitamin D.

Additional tips
To estimate how much calcium you’re currently getting, start with the assumption that a basic healthy diet provides about 250 mg of calcium in bits and pieces from a variety of foods that are not what we classify as calcium-rich.

For adults to meet calcium recommendations without a supplement means about 3 servings of calcium-rich foods each day.

Calcium-Rich Foods (about 300 mg calcium per serving)
Milk or Fortified Soymilk                                    8 ounce glass
Regular Yogurt* (or Fortified Soy Yogurt)         8 ounces 
Cheese*                                                           1  1/2 ounces
Calcium-fortified Juice                                       8 ounces
Extra Firm Tofu (if made with calcium)              4 ounces
Sardines (with bones)                                      3 ounces
Kale or collard greens*                                    1-1 ½ cups cooked

*Other foods with extra calcium

~Greek-style Yogurt is less concentrated in calcium, with about 170-200 mg in a 6-oz container
~Cottage Cheese contains about 150-200 mg per cup
~Calcium-fortified Cereal may contain 150 mg or more per standard serving (check Nutrition Facts panel on label)
~Soft or Silken Tofu (if made with calcium) is lower in calcium than firm types, with about 130 mg in a 4-oz serving
~Bok choy also provides calcium, about 160 mg per cup cooked.  Several other dark green leafy vegetables like spinach, beet greens and chard are so high in oxalate that our bodies cannot efficiently absorb the calcium they contain, so these aren’t significant sources of calcium.

Checking food labels for calcium content? The Daily Value (DV) for calcium is 1000 mg.  So if the listed serving size provides 30% of DV, that means 300 mg of calcium.  Check to see how your portion compares to that standard serving size, and you’ll know how much calcium you’re getting from that food.

Calcium is best absorbed in amounts of no more than 500 mg at a time, so spread consumption out through the day.

The next big question
Have you heard people say that you need extra magnesium or potassium to use calcium for healthy bones?  In the next section of my interview with Dr. Nieves, you’ll get the straight scoop on that.
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Resources:
The latest recommendations on calcium and vitamin D for all ages are explained in this report from the Institute of Medicine, part of the National Academy of Sciences:  Dietary Reference Intakes for Calcium and Vitamin D, published 2011.

For general information about osteoporosis, check the Bone Health section of the National Institutes of Health website and the website of the National Osteoporosis Foundation.