Osteoporosis or low bone mass affects 55 percent of people over age 50 in the United States, according to the International Osteoporosis Foundation. A study of 1,064 women followed for 15 years shows that not getting enough calcium is associated with smaller spinal bones and weaker spines (Osteoporosis International, January 18, 2019). You need an adequate amount of calcium to keep your bones strong (Maturitas, 2018;107:7), but many people take calcium pills when they should be getting their calcium from foods. Calcium pills have not been shown to strengthen bones and they can have many serious side effects.
A review of 33 studies showed that calcium pills, taken both with and without vitamin D pills, do not prevent fractures, regardless of dose (JAMA, Dec 26, 2017;318(24):2466). One review of 59 studies and another reviewing 50 studies showed that neither calcium pills nor foods rich in calcium prevent bone fractures (British Medical Journal, September 29, 2015;351:h4183 ). An editorial in the same issue states that the evidence is so overwhelming that calcium pills do not prevent fractures that we have to ask ourselves why these products are still sold today.
Why Food Sources of Calcium Are Better
No evidence exists that consuming more calcium than the recommended dietary allowance will result in better bone health or any other health benefits (Ann Intern Med, October 25, 2016). Researchers at Johns Hopkins followed 2700 people who took calcium pills for ten years and found that they had a 22 percent increased risk of arteriosclerotic calcium plaques forming in the arteries leading to their hearts, compared to those who did not take calcium pills (Journal of the American Heart Association, October 11, 2016). This confirms other studies associating arterial plaque formation with calcium pills (Heart, Jun 2012;98(12):920-5). On the other hand, people who took in large amounts of calcium from food (>1400 milligrams per day) were 27 percent less likely to have this buildup of plaques. This suggests that calcium in pills is processed differently from calcium in foods, to accumulate in body tissues rather than in bones and to increase risk for heart attacks (J Clin Hypertens (Greenwich), May 2, 2017) and strokes (Journal of the American Heart Association, October 10, 2016). Nobody really knows why several recent studies associate health dangers with taking calcium pills. It could be that calcium pills contain calcium salts that cause a higher rise in blood calcium than calcium in foods, so that calcium from pills enters arteries, brain and kidneys at higher concentrations.
Other Side Effects of Calcium Pills
Calcium from supplements can accumulate in:
• arteries, to increase heart attack risk (British Medical J, 2011;342:d2040; JAMA Intern Med, 2013;173:639-46; NEJM, October 17, 2013; Heart, 2012;98:920-925; Endocrine Practice, published online August 19, 2011; The Oncologist, 2012;17:1171-1179). However, researchers at Harvard found no association between calcium pills and increased risk for heart attacks (Osteoporosis International, May 2014)
• kidneys, to increase kidney stone risk (Am J Clin Nutr, July 2011;94(1):270-277; NEJM, 2006;354:669-83)
• stomach, to cause acid rebound and increase hospital admissions for acute stomach ulcer bleeding (J Bone Miner Res, 2012;27:719-22)
• blood, to cause high blood calcium levels that can cause nausea, vomiting, confusion and seizures
• eyes, linked to macular degeneration (JAMA Ophthalmology, April 2015)
• prostate, to possibly increase risk for prostate cancer (Ann Epidemiol, 2009;19:96-102)
• colon, to cause constipation and increase risk for pre-malignant serrated colon polyps (Gut, March 02, 2018). Serrated colon polyps are full of Annexin A10 and calcium pills may increase the concentration of that chemical. Serrated polyps are associated with a markedly increased risk for developing colon cancer (Gut, November 2016;67(3)).
Calcium from pills can also bind to other drugs, such as antibiotics and osteoporosis medications, to prevent them from being absorbed into your bloodstream, and they can block the benefits of drugs such as calcium-channel blockers and beta blockers.
Why So Many Calcium Pills?
In 1994, the U.S. Congress passed a law that allows manufacturers of calcium and vitamin D pills to advertise and sell their pills without having to supply evidence that their products have any health benefits at all. More than $6 billion of calcium pills and $2.5 billion of vitamin D are sold each year. In 2013, the United States Preventive Services Task Force reviewed 135 studies and recommended that postmenopausal women refrain from taking supplemental calcium and vitamin D.
Diet and Exercise to Strengthen Bones
At this time, the best ways we have to keep your bones strong are:
• eat a plant-based diet with a wide variety of foods that are rich in calcium, such as leafy-green vegetables, seafood, whole grains, beans and dairy products (preferably cheese and yogurt)
• restrict red meat, all sugar-added foods and sugared drinks including fruit juices
• restrict alcohol
• do not smoke and avoid second-hand smoke
• try to exercise regularly against increasing resistance
• keep your blood levels of hydroxy vitamin D above 20 ng/ml. See Sunlight: More than Vitamin D.
An anti-inflammatory, plant-based diet helps to prevent loss of bone density and fractures in postmenopausal women (J Bone Miner Res, May 2017;32(5):1136-1146; American Journal of Clinical Nutrition, Dec 22, 2016; Eur J Nutr, Aug 24, 2016) and to prevent osteoporosis of the spine and hip (Open Journal of Epidemiology, May 2013;3(2):79-84). Older men who ate the most dietary fiber in cereals, fruits, vegetables, nuts and beans had the least hip bone loss as they aged (J Bone and Min Res, October 13, 2017). With aging, all men and women on the typical Western diet are at high risk for osteoporosis and broken bones (Am J Physiol Renal Physiol 2003;284:F32-40), and a pro-inflammatory diet has been linked to increased hip fracture rates (Osteoporosis International, October 13, 2017).
Don’t eat meat three times a day: A low-protein diet, particularly in people over 60, can weaken bones (Int J Vitam Nutr Res, 2011;81(2-3):134-42), but several studies show that eating a high-protein diet makes the blood acidic to increase calcium loss through the kidneys, so too much protein can also weaken bones (J Nutr, 1998;128:1051-53). The general feeling today is that a reasonable intake of protein (1.5 g /kg/day) will not weaken bones (Am J Clin Nutr, 2003;78(suppl):S584-92). Acid-forming foods such as meat, fish and eggs have been shown to increase calcium loss through the kidneys, while alkaline-forming foods from plants help your kidneys retain calcium (J Nutr, 2003;133(suppl):S850-1). Most young people do not need to worry about protein, and older people can meet their needs for protein by eating reasonable amounts of nuts, beans, whole grains, and animal protein (seafood, poultry, cheese, yogurt).
Avoid sugar-added foods and drinks: High blood sugar levels weaken bone matrices and increase fracture risk long before bones lose enough calcium to have an abnormally low bone density test (J Clin Endocrinology & Metabolism, published online December 21, 2016). This means that a high blood-sugar level (insulin resistance) weakens bones to increase risk for bone fractures, even if bone density tests are normal. Young people who were not diabetic but who had high blood sugar levels after meals were found to have smaller and weaker bones than non-diabetic men who did not have high rises in blood sugar after meals. People who are not diabetic, but have high rises of blood sugar after meals, are at significantly increased risk for bone fractures (Bone, Jan 4, 2019). Foods that cause a high rise in blood sugar include sugar-added foods, all sugared drinks, and red meat, which blocks insulin receptors. Fruits also cause a high rise in blood sugar but fruits have not been shown to have the same harmful effects of increased risk for arterial damage, heart attacks and strokes.
Avoid diabetes: Diabetics suffer a very high rate of osteoporosis (Diabetes & Metabolism, June 2008;34(3):193-205) and bone fractures (J Bone and Min Res, November 2012;27(11):2231-2237). The bones of diabetics are significantly weaker than those of non-diabetics (Bone, Dec 2015;81:152-160). Since obese people often have big bones, doctors used to think that excess weight strengthened bones, but it does not. Excess body fat causes higher rises in blood sugar after meals. Overweight diabetics are at very high risk for osteoporosis and bone fractures. When blood sugar levels rise too high, sugar sticks to the outer membranes of every cell in your body including the matrix of bones, which weakens them and increases fracture risk (World J Diabetes, Aug 15, 2013;4(4): 101-113).
Exercise: Everything that causes you to lose muscle size and strength also causes you to lose bone size and strength (Am J Clin Nutr, May 2008;87(5):1567S-1570S). Anything that enlarges muscles also makes bones larger and stronger.
You can help to prevent and treat osteoporosis by exercising against resistance, eating a plant-based anti-inflammatory diet that restricts red meat, processed meats and sugar-added foods, meeting your needs for calcium by eating a variety of calcium-rich foods, avoiding excess weight, avoiding smoking and restricting alcohol.