March 23, 2015

Can We get Enough Calcium from a Regular Diet?


While we tend to think of calcium as a supplement for healthy bones, new research suggests that our need for calcium goes way beyond bone health.

In this article, we will discuss the new research, our calcium needs, the benefits, the risks and how to get the proper amount of calcium safely.

A Lesson in Calcium from our Ancestors.

Since early in the evolutionary process, our ancestors ingested significant amounts of calcium in their diets. Hunter-gatherers would eat all parts of the animals they caught, including chewing on or sucking the calcium-rich marrow from the bones.

Once the domestication of animals took hold some 10,000-15,000 years ago, calcium-rich dairy products fed our genetic need for a calcium-rich diet. Even without meat or dairy in the diet, hunter-gatherers foraged plenty of calcium-rich greens, fruits and tubers, legumes and grains—this is one mineral we were not meant to be without!

How Much Calcium Do We Need?

Most of the negative concerns about calcium is due to overuse of calcium supplements. The risks of over-supplementing with calcium may include kidney stones and cardiovascular issues. So, getting the right amount is important. (3)

Unlike other minerals, calcium is abundant in the foods of a healthy diet, and even folks not tuned into nutritional health likely get enough calcium from all the calcium-fortified foods on the market. I suggest doing a quick check of your regular diet to make sure you are getting enough calcium from your foods (see the calcium food chart below). The Recommended Dietary Allowance (RDA) for adults is 1,000-1,200mg/day. (14) Reaching the RDA should be pretty easy for most folks to accomplish solely from their foods.

Fortified foods are typically highly processed and I suggest avoiding them if possible.

A serving of yogurt, salmon, cheese, beans, and a couple servings of veggies each day gets your calcium in the daily “safe zone.” For those of you who do not trust the FDA to make dietary recommendations, in this case, there are numerous studies suggesting that the RDA is pretty accurate—you don’t want more and you don’t want less. (14,15)

Support Your Colon.

New research is suggesting that adequate calcium from supplementation and calcium-rich foods may support healthy cell division of the cells that line the colon and rectum. In a large meta-analysis, findings supported what many previous studies have also found that: a higher calcium intake is mechanically linked with colon rectal health and the healthy timing for cell replication, division and death. (1)

Calcium seems to support colon health by attaching to bile acids in the colon that are attached to toxic fat-soluble chemicals. The calcium may protect the colon from these chemicals that may irritate or adhere to the intestinal lining. Calcium has also been shown to slow the rate of division of the epithelial cells of the colon and rectum and promote healthy cell replication. (1)

The Power Couple: Vitamin D and Calcium.

Without Vitamin D, the calcium is not able to leave the intestinal tract. (7) Clearly, it is the combination of Vitamin D and calcium that team up to deliver the calcium benefits I discuss in this article. With vitamin D levels being deficient in more than half the population, both calcium and Vitamin D levels must both be optimized to make best use of the benefits listed below.

Click here for more on Vitamin D.

More Calcium Benefits

Here are a few of the well-documented benefits of maintaining healthy calcium levels in the blood:

  • Supports healthy bones (2)
  • Buffers excess acid in stomach (2)
  • Supports healthy weight loss (2)
  • Support menopausal transition (2)
  • Supports healthy cell replication (2)
  • Supports healthy blood clotting (12)
  • Supports healthy blood pressure (2)
  • Healthy muscle contractions
  • Supports healthy circulation (11)
  • Supports efficient transmission of nervous system messages (10)
  • Secretion of hormones (9)
  • Secretion of enzymes (8)

Do I Need To Supplement With Calcium?

The question that asks why rural women in China or India compared to American women have greater bone density as they age without every taking calcium supplements has challenged researchers for years. According to the ancient wisdom of Ayurveda, healthy bones are a part of a very elaborate digestive process that takes up to 30 days to complete.

Today, research is suggesting that the lack of microbial diversity (beneficial bacteria) in the gut may be responsible for the bone density issues we see in the West. (6) This could explain why women in traditional and rural cultures have healthy bone density without supplementation. According to Ayurveda, healthy digestion is a requirement for healthy bones and we now know it is a requirement for the microbial diversity that we lack in the west.

As a maintenance strategy for your bones it is important to get and maintain 1,000-1,200mg of calcium per day in your diet. (14) Check your diet against the list below. Make sure your Vitamin D3 is optimized or the calcium will be ineffective. The Vitamin D Council recommends testing Vitamin D3 levels regularly and maintaining levels of 40-80ng/mL of Vitamin D3 year round. (13) If you do not have access to Vitamin D testing, see our at-home Vitamin D test kit.

To support healthy microbes in the intestines, make sure you are addressing any underlying digestive issues. Just avoiding a food you do not seem to tolerate is not enough. While that might help you not experience the digestive symptom, it is a sign of a digestive imbalance that may be altering the very delicate intestinal environment required for healthy microbial diversity.

Consider adding small amounts of fermented foods to your diet such as, kimchi, natto, yogurt, cheese, fermented veggies, olives and others; but be sure to take these in small amounts (condiment size). Also, consider a colonizing, rather than transient probiotic. Colonizing probiotics adhere to the gut wall and proliferate new strains of microbes that become productive permanent residents. While research on these is rare, one such strain is Bifidobacterium lactis HN019 (learn more here).

Supplements for Bone Support.

While most folks do not need to supplement with calcium, when trying to build healthy bones, the right kind of calcium supplementation is important. The concept of supplementing with forms of calcium-rich bone meal has been used successfully for years. The body seems to absorb the calcium better when it is delivered with a host of other nutrients, minerals and proteins also found in natural bone. A well-researched form of this bone support is called microcrystalline hydroxyapatite (MCHC). The MCHC delivers calcium, phosphorous, trace minerals, peptides, growth factors, collagen and amino acids that support healthy bone function and are naturally found in healthy bones. (5)

Vitamin K2 helps support healthy bones by activating the bone-building osteocalcin protein, which helps attach calcium to the mineral bone matrix. It also protects the bone from being reabsorbed by the body. (3) Vitamin K2 is naturally manufactured in the large intestine by microbes, however, many folks do not have the microbial diversity to supply the body with adequate Vitamin K2.

Vitamin K2 is converted from K1 which found in veggies, but not in very large amounts. It is also found in cheese and other fermented foods which, for most folks, should be enough. But, when trying to build bone, consider vitamin K2 as a supplement. Learn more about K2 here.

Remember, the benefits of calcium are greatly enhanced with optimized vitamin D3 levels.


A Guide to Calcium-Rich Foods

Produce Serving Size Estimated Calcium*
Collard greens, frozen 8 oz 360 mg
Broccoli rabe 8 oz 200 mg
Kale, frozen 8 oz 180 mg
Soy Beans, green, boiled 8 oz 175 mg
Bok Choy, cooked, boiled 8 oz 160 mg
Figs, dried 2 figs 65 mg
Broccoli, fresh, cooked 8 oz 60 mg
Oranges 1 whole 55 mg
Seafood Serving Size Estimated Calcium*
Sardines, canned with bones 3 oz 325 mg
Salmon, canned with bones 3 oz 180 mg
Shrimp, canned 3 oz 125 mg
Dairy Serving Size Estimated Calcium*
Ricotta, part-skim 4 oz 335 mg
Yogurt, plain, low-fat 6 oz 310 mg
Milk, skim, low-fat, whole 8 oz 300 mg
Yogurt with fruit, low-fat 6 oz 260 mg
Mozzarella, part-skim 1 oz 210 mg
Cheddar 1 oz 205 mg
Yogurt, Greek 6 oz 200 mg
American Cheese 1 oz 195 mg
Feta Cheese 4 oz 140 mg
Cottage Cheese, 2% 4 oz 105 mg
Frozen yogurt, vanilla 8 oz 105 mg
Ice Cream, vanilla 8 oz 85 mg
Parmesan 1 tbsp 55 mg
Fortified Food Serving Size Estimated Calcium*
Almond milk, rice milk or soy milk, fortified 8 oz 300 mg
Orange juice and other fruit juices, fortified 8 oz 300 mg
Tofu, prepared with calcium 4 oz 205 mg
Waffle, frozen, fortified 2 pieces 200 mg
Oatmeal, fortified 1 packet 140 mg
English muffin, fortified 1 muffin 100 mg
Cereal, fortified 8 oz 100-1,000 mg
Other Serving Size Estimated Calcium*
Mac & cheese, frozen 1 package 325 mg
Pizza, cheese, frozen 1 serving 115 mg
Pudding, chocolate, prepared with 2% milk 4 oz 160 mg
Beans, baked, canned 4 oz 160 mg


Source: National Osteoporosis Foundation; http://nof.org/articles/886.

1.Calcium intake and colorectal cancer risk. Int J Cancer. 2014 Oct 15;135(8): 1940-8.

2. Vitamins & minerals health centre: Calcium

BMJ health news: Calcium supplements: helpful in moderation, harmful in excess.
Journal of the American Society of Nephrology: Got Calcium? Welcome to the Calcium-Alkali Syndrome.
Longe JL ed, The Gale Encyclopaedia of Alternative Medicine, second edition, 2004.
Office of Dietary Supplements web site: “Calcium.”
Natural Marketing Institute’s 2007 Health and Wellness Trends Database.
Natural Standard Patient Monograph, “Calcium”.
WebMD Feature: “Boning up on Calcium: Supplements for Bone Health.”
COMA (1998).
Nutrition and Bone Health: with particular reference to calcium and vitamin D.
Report of the Subgroup on Bone Health, Working Group on the Nutritional Status of the Population, Committee on Medical Aspects of Food and Nutrition Policy.
The Stationery Office, London.
The Food Standards Agency website: “Calcium”.
NHS Choices. Health Supplements Information Service

Medically Reviewed by Dr Rob Hicks on March 18, 2015 © 2015 WebMD, LLC. All rights reserved.

3. Kidney stone disease and risk factors for coronary heart disease. Int J Urol. 2005 Oct;12(10):859-63.

4. Management of osteoporosis: is there a role for vitamin K? Int J Vitam Nutr Res. 1997;67(5):350-6.

5.Microcrystalline hydroxyapatite compound in prevention of bone loss in corticosteroid-treated patients with chronic active hepatitis. Postgrad Med J. 1985 Sep; 61(719): 791–796.

6.The gut microbiota regulates bone mass in mice. J Bone Miner Res. 2012 Jun;27(6):1357-67. doi: 10.1002/jbmr.1588.

7.Vitamin D supplementation and calcium absorption during caloric restriction: a randomized double-blind trial. Am J Clin Nutr. 2013 Mar;97(3):637-45. doi: 10.3945/ajcn.112.044909. Epub 2013 Jan 30.

8. The relationship between calcium exchange and enzyme secretion in the isolated rat pancreas. J Physiol. 1973 Nov;235(1):75-102.

9. Function-specific calcium stores selectively regulate growth hormone secretion, storage, and mRNA level. Am J Physiol Endocrinol Metab. 2002 Apr;282(4):E810-9.

10. Further study of the role of calcium in synaptic transmission.  J Physiol. 1970 May; 207(3): 789–801.

11. Effects of calcium channel blockers on the coronary circulation. Am J Hypertens. 1990 Dec;3(12 Pt 2):299S-304S.

12. Blood clotting: the function of electrolytes and of calcium.  Biochem J. 1952 Jan; 50(3): 415–420.

13. http://www.vitamindcouncil.org/about-vitamin-d/testing-for-vitamin-d/#

  •  Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM; Endocrine Society. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011 Jul;96(7):1911-30.
  • Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.
  • Vieth, R. “The Pharmacology of Vitamin D.” In Vitamin D, Third Edition, by Feldman D, Pike JW and Adams JS. Elsevier Academic Press, 2011.

14. New Recommended Daily Amounts of Calcium and Vitamin D. Source: Institute of Medicine, December 2010 http://www.nlm.nih.gov/medlineplus/magazine/issues/winter11/articles/winter11pg12.html

15. The 2011 Report on Dietary Reference Intakes for Calcium and Vitamin D from the Institute of Medicine: What Clinicians Need to Know.  J Clin Endocrinol Metab. 2011 Jan; 96(1): 53–58.  Published online 2010 Nov 30. doi:  10.1210/jc.2010-2704


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Author: Dr. John Douillard

Editor: Travis May

Photo: Wikipedia

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