noun_Search_345985 Created with Sketch.
0 cart-active Created with Sketch. noun_Search_345985 Created with Sketch.

Calcium: A Team Sports View of Nutrition

By Christopher Clark
September 26, 2016
Calcium: A Team Sports View of Nutrition image

Every four years, the world comes together to celebrate the Olympic games. Olympic sports are broadly classified as either team- or individually-based. Soccer and volleyball, for example, are team sports, whereas boxing and tennis are more individual.

With individual sports, coaches, trainers, and physical therapists play supporting roles to the individual who gets the spotlight. With team sports, winning usually requires strong team dynamics and success stories are almost always collaborative efforts.

Nutrition is the same way. We often focus on certain key nutrients without understanding the importance of nutrient interactions, ratios, and synergies.

Calcium is an excellent example.

Most of us grew up being constantly reminded to drink more milk, ostensibly to obtain enough calcium. Certainly we require dietary calcium, but for optimal health, we need to view calcium holistically, as one player working in concert with many other key nutrients.

Meet the team

Calcium is essential for strong, healthy bones and teeth. It also plays vital roles in hormone regulation, muscle function, and proper heart and blood vessel function. When calcium and associated nutrient levels are properly balanced, bone strength is optimized while fracture risk is minimized.

However, when calcium is out-of-balance with the other essential nutrients more than just our bones suffer. The risk of arterial calcification and resultant cardiovascular disease increases. So which key nutrients support calcium balance?

Vitamin D

Insufficient vitamin D inhibits calcium absorption within the intestines.1 This means even if you consume adequate calcium, you might not absorb enough if your vitamin D levels are below normal. Vitamin D status is so important that, according to the authors of a major review for the American Society for Bone and Mineral Research, vitamin D is a better predictor of bone mineral density than calcium.2 This is especially relevant considering that 42% of US adults are vitamin D deficient, with deficiency rates being even higher among blacks (82%) and Hispanics (69%).3


Magnesium is another essential mineral with respect to calcium. Roughly half of US adults have low magnesium, which is associated with type-2 diabetes, metabolic syndrome, hypertension, atherosclerotic vascular disease, sudden cardiac death, osteoporosis, migraine headaches, asthma, and colon cancer.4 One of the most powerful predictors of all-cause mortality and cardiovascular events is vascular calcification – the accumulation of calcium within the arteries, which is associated with atherosclerosis.5,6,7 Various factors promote vascular calcification, including low magnesium levels.8,9 The optimum ratio of calcium to magnesium is around 2:1. Focusing on calcium without considering magnesium is problematic.10

Vitamin K

Vitamin K works synergistically with other fat-soluble vitamins, like D and A, to maintain serum calcium concentrations and for bone tissue maintenance. Vitamin K (in its various forms) appears to play significant roles in reducing both arterial calcification and bone fracture risk.11,12,13 Optimal ratios of calcium to vitamins K1 and K2 have not been established, but these K vitamins play such a critical role on “team calcium,” that vitamin K supplementation may be an important health strategy.14,15


It has been established that protein consumption promotes increased urinary calcium excretion. Knowing this, some researchers have suggested that lower protein diets are optimal for calcium balance and general bone health. They have gone as far to say that vegetable protein is better than animal protein.

Such conclusions, however, ignore the evidence linking low protein consumption to decreased calcium absorption.16 The RDA for protein is 0.8 grams per kg body weight, but optimal levels for calcium homeostasis range from 1.0 to 1.5 grams.17 This means that calcium absorption becomes more efficient as protein consumption increases. As summarized in an American Journal of Clinical Nutrition review, “concerns about dietary protein increasing urinary calcium appear to be offset by increases in absorption. Likewise, concerns about the impact of protein on acid production appear to be minor compared with the alkalizing effects of fruits and vegetables.”18

A Paleo diet promotes this balance of healthy protein consumption along with plenty of fruit and vegetables to optimize calcium absorption.

Potassium/sodium – A key ratio in acid load

Net acid-alkaline load is an important component of health. Evidence suggests that ancestral diets were net-alkaline, thereby contributing to our ancestors’ strong bones.19,20 In other words, although they ate animal protein (net acid), they ate proportionally more vegetables, fruits, and other net-alkaline foods.

A further benefit of increased vegetable consumption is higher potassium to sodium ratios. The Institute of Medicine’s recommended ratio is 2.0, which is on par with ancestral diets, but roughly 10 times higher than ratios observed in contemporary diets.21,22 With respect to calcium, this is significant because higher potassium to sodium ratios may help the body conserve calcium more effectively.23

Conclusion: Team tactics with a Paleo Diet

Calcium is much more of a “team sport” than an isolated nutrient. Which is why simply drinking a glass of milk or taking a calcium supplement may have disappointing results.

Getting “enough” calcium necessitates concurrently getting enough vitamin D, magnesium, vitamin K, protein, potassium, and more. This may sound complicated, but the Paleo diet is the ideal template for consuming these nutrients in their proper ratios. In some cases, supplementation of vitamins D and K may be prudent. For an in-depth look at achieving and maintaining calcium balance, check out Marc Bubb’s part two in this series covering how to maximize your calcium balance on a Paleo Diet.

More in September Series: All About Calcium

Promoting calcium balance health on a Paleo Diet (easier than you think) By Dr. Marc Bubbs ND, CISSN, CSCS

Coconut milk: a Dairy alternative By Nell Stephenson


[1] Christakos S. (Jul 1, 2012). Recent advances in our understanding of 1,25-dihydroxyvitamin D(3) regulation of intestinal calcium absorption. Archive of Biochemistry and Biophysics, 525(1). Retrieved from //

[2] Bischoff-Ferrari HA, et al. (May 2009). Dietary calcium and serum 25-hydroxyvitamin D status in relation to BMD among U.S. adults. Journal of Bone and Mineral Research, 24(5). Retrieved from //

[3] Forrest KYZ, et al. (Jan 2011). Prevalence and correlates of vitamin D deficiency in US adults, Nutrition Research, 31(1). Retrieved from //

[4] Rosanoff A, et al. (Mar 2012). Suboptimal magnesium status in the United States: are the health consequences underestimated? Nutrition Reviews, 70(3). Retrieved from //

[5] Shaw LJ, et al. (Jul 7, 2015). Long-Term Prognosis After Coronary Artery Calcification Testing in Asymptomatic Patients: A Cohort Study. Annals of Internal Medicine, 163(1). Retrieved from //

[6] Rennenberg RJ, et al. (2009). Vascular calcifications as a marker of increased cardiovascular risk: A meta-analysis. Vascular Health Risk Management, 5. Retrieved from //

[7] Shroff RC and Shanahan CM. (Mar-Apr 2007). The vascular biology of calcification. Seminars in Dialysis, 20(2). Retrieved from //

[8] Bloom S and Peric-Golia L. (Aug 1989). Geographic variation in the incidence of myocardial calcification associated with acute myocardial infarction. Human Pathology, 20(8). Retrieved from //

[9] Vlad M, et al. (Mar 2000). Magnesium and calcium concentration in the abdominal aorta of patients deceased by ischemic heart disease. Magnesium Research, 13(1). Retrieved from //

[10] Durlach J. (Sep 1989). Recommended dietary amounts of magnesium: Mg RDA. Magnesium Research, 2(3). Retrieved from //

[11] Cockayne S, et al. (Jun 2006). Vitamin K and the Prevention of Fractures Systematic Review and Meta-analysis of Randomized Controlled Trials. JAMA Internal Medicine, 166(12). Retrieved from //

[12] Rennenberg RJ, et al. (Apr 2010). Calcium scores and matrix Gla protein levels: association with vitamin K status. European Journal of Clinical Investigation, 40(4). Retrieved from //

[13] Schurgers LJ, et al. (Apr 2010). The circulating inactive form of matrix gla protein is a surrogate marker for vascular calcification in chronic kidney disease: a preliminary report. Clinical Journal of the American Society of Nephrology, 5(4). Retrieved from //

[14] Manna P, et al. (Jul-Aug 2016). Beneficial role of vitamin K supplementation on insulin sensitivity, glucose metabolism, and the reduced risk of type 2 diabetes: A review. Nutrition, 32(7-8). Retrieved from //

[15] Shea MK, et al. (Jun 2009). Vitamin K supplementation and progression of coronary artery calcium in older men and women. American Journal of Clinical Nutrition, 89(6). Retrieved from //

[16] Kerstetter JE, et al. (Sep 2003). Dietary protein, calcium metabolism, and skeletal homeostasis revisited. American Journal of Clinical Nutrition, 78(3). Retrieved from //

[17] Kerstetter JE, et al. (Sep 2003). Dietary protein, calcium metabolism, and skeletal homeostasis revisited. American Journal of Clinical Nutrition, 78(3). Retrieved from //

[18] Heaney RP and Layman DK. (May 2008). Amount and type of protein influences bone health. American Journal of Clinical Nutrition, 87(5). Retrieved from //

[19] Cordain L, et al. (Feb, 2005). Origins and evolution of the Western diet: health implications for the 21st century. American Journal of Clinical Nutrition, 81(2). Retrieved from //

[20] Ströhle A, et al. (Oct 2010). Latitude, local ecology, and hunter-gatherer dietary acid load: implications from evolutionary ecology. American Journal of Clinical Nutrition, 92(4). Retrieved from //

[21] Adrogué HJ and Madias NE. (May 2007). Sodium and Potassium in the Pathogenesis of Hypertension. New England Journal of Medicine, 356(19). Retrieved from //

[22] Büssemaker E, et al. (Jun 2010). Pathogenesis of hypertension: interactions among sodium, potassium, and aldosterone. American Journal of Kidney Diseases, 55(6). Retrieved from //

[23] Frassetto L, et al. (Feb 2005). Long-term persistence of the urine calcium-lowering effect of potassium bicarbonate in postmenopausal women. Journal of Clinical Endocrinology and Metabolism, 90(2). Retrieved from //

Even More Articles For You

What to Eat If You’re Intermittent Fasting
Your success with intermittent fasting can depend on many things. Critical among them are the foods you eat between periods of fasting. We take a closer look at why this is.
By Megan Patiry
What Does “Plant-Based” Really Mean?
There are several definitions for the plant-based diet trend. We explore what they are, and how The Paleo Diet can fit into this plan.
By Betsy Schroeder
What to Eat This Week: September, Week 4
This week’s meal plan will help you strengthen your immunity for cold and flu season!
By Aimee McNew
Paleo Leadership
Trevor Connor
Trevor Connor

Dr. Loren Cordain’s final graduate student, Trevor Connor, M.S., brings more than a decade of nutrition and physiology expertise to spearhead the new Paleo Diet team.

Mark J Smith
Dr. Mark J. Smith

One of the original members of the Paleo movement, Mark J. Smith, Ph.D., has spent nearly 30 years advocating for the benefits of Paleo nutrition.

Nell Stephenson
Nell Stephenson

Ironman athlete, mom, author, and nutrition blogger Nell Stephenson has been an influential member of the Paleo movement for over a decade.

Loren Cordain
Dr. Loren Cordain

As a professor at Colorado State University, Dr. Loren Cordain developed The Paleo Diet® through decades of research and collaboration with fellow scientists around the world.