By Helaine Krasner, MS, RDN, CSOWM, CDN

Calcium is commonly known for its important role in bone health, but it is also needed for proper nerve and muscle function. This essential mineral also plays a role in blood clotting, enzyme function and maintaining a normal heart rhythm. Our body stores calcium in bones and teeth, and normal blood levels are tightly regulated mainly by fluctuations in parathyroid hormone. When intake is inadequate this hormone signals our body to extract calcium from our bones.

Many people don’t get enough.

Almost 30 percent of men and 60 percent of women over the age of 19 do not consume enough calcium, and more than 90 percent do not get enough vitamin D. Vitamin D aids in calcium absorption. Long-term exposure to inadequate calcium intake or absorption can result in osteoporosis, which affects about 17 percent of women and 5 percent of men.


Who is at highest risk?

People who follow a vegan diet or those with lactose intolerance may struggle to get enough calcium in their diet. Long-term use of corticosteroid medications and inflammatory bowel diseases both decrease calcium absorption. In addition, chronic use of proton pump inhibitors, a common treatment for reflux or GERD, and bariatric surgery procedures that bypass part of the small intestine result in decreased calcium absorption. Postmenopausal women are also at risk because decreased estrogen production reduces calcium absorption and increases urinary calcium loss.


How much do we need? 

The Recommended Daily Allowance (RDA) for calcium intake is 1000mg/day for adults or 1200mg/day for women over 50 and men over 70. (The RDA for vitamin D is 600 IU daily for both men and women.)


Where can we get it?

Dairy foods are considered the best source of calcium, with milk and yogurt being the most nutrient dense. The recommended daily intake for adults is three-cup equivalents. About 90 percent of the U.S. population does not consume recommended amounts of dairy. Dark leafy greens may be considered a good alternative source for calcium, but absorption is limited by the oxalic and phytic acids they also contain.


Calcium content in foods:


Serving size        Food                                                               Calcium (grams)

1 cup                   nonfat yogurt                                                488

1 cup                   calcium fortified almond milk                        442

1 cup                   low fat yogurt                                                415

½ cup                  firm tofu                                                        253 (if prepared with calcium sulfate)

1 cup                   calcium fortified orange juice                       349

1.5 oz                  part skim mozzarella                                    333

3 oz.                    canned sardines                                          325

1 cup                   low fat milk                                                   305

1 cup                   fat free milk                                                   299

1 cup                   calcium fortified soymilk                               299

1 cup                   low fat Greek yogurt                                     260

1 cup                   nonfat Greek yogurt                                     250

1 cup                   cooked mustard greens                               284

1 cup                   cooked collard greens                                 268

1 cup                   cooked spinach                                           245

1 cup                   cooked bok choy                                         185

1 cup                   cooked kale                                                 177

3 oz.                    canned salmon with bones                          181

1 Tbsp                 tahini (sesame paste)                                  154

1 cup                   low fat cottage cheese                                 138

¼ cup                  almonds                                                       100


For those who are not able to consume enough dairy or calcium fortified foods a supplement is a good option. Aim to stay within the RDA from foods and supplements. The Tolerable Upper Limit from supplements is 2500mg/day for adults or 2000mg/day for women over 50 and men over 70 to avoid possible health risks associated with over-supplementation. Always consult a healthcare professional before taking dietary supplements.





Helaine Krasner, MS, RDN, CSOWM, CDN is a registered dietitian nutritionist who takes great pride in helping our Bariatric and Medical Weight Management patients achieve their health and weight loss goals.