Doctors and prestigious national organizations routinely recommend taking calcium supplements to support good bone health. In fact, the Centers for Disease Control reports that 60% of American women over age 60 take them. But based on recent research, experts now question whether these recommendations are a good idea. Confirming two meta-analyses published in 2010 and 2011, Dr.. Kuanrong Li and colleagues recently reported an association between calcium supplementation and heart attacks. After following 24,000 Germans for 11 years, researchers found heart attacks increased by 86% among people taking supplements including calcium, and increased by 200% among people who used calcium as their only dietary supplement.
Admittedly, there were several problems with this study:
- Because only a small number of people experienced a heart attack, a small change in the number would dramatically increase or decrease the reported ‘risk’.
- It did not demonstrate similar findings for stroke and cardiovascular death, which share similar intermediate pathways; thus, the strength of the association is not robust.
- Only 55% of the participants reported the names of the supplements, and only 3.6% reported ‘taking calcium supplements.’
- Surveys did not ask for information on calcium dosage, type, or whether it was taken with Vitamin D, magnesium, or Vitamin K – all useful factors to provide the public with more specific recommendations.
Despite this study’s limitations, the totality of research published suggests similar findings. Therefore, I have changed my perspective: I now recommend people obtain their recommended daily calcium intake from dietary sources and take supplements only on days when diet does not achieve these goals.
How much calcium is enough to prevent fractures?
The National Osteoporosis Foundation and National Academy of Science recommend:
- For women under age 50 and men under 70: 1,000 mg of calcium daily
- For women over 50 and men over 70: 1,200 mg of calcium daily
However, other research has found that 700 mg of calcium may be sufficient, and higher doses do not necessarily provide additional bone health benefits. Remember, calcium must be consumed with adequate Vitamin D in order to confer bone health protection.
What are calcium-rich foods?
Most individuals can obtain a significant portion of their daily calcium needs from calcium-rich foods like low-fat and fat-free dairy products, green vegetables such as collard greens and broccoli, and calcium-fortified foods.
How do I choose the right calcium supplement formulation?
If you do not get enough calcium from your diet, discuss with your physician whether taking calcium supplementation is right for you. Note also:
1. Research has not determined if different calcium supplement formulations (such as calcium carbonate, calcium citrate, coral calcium) have distinct health effects or risks.
2. Research has determined that:
- Calcium carbonate requires an acidic environment in the stomach for proper absorption and is better absorbed when taken with a meal.
- Calcium citrate is the preferred calcium supplement formulation if you are elderly, taking proton pump inhibitor or H2 blocker medication, have inflammatory bowel disease or absorption disorders, or have difficulty taking calcium supplements with a meal.
BOTTOM LINE:
1. Get your calcium needs met by eating calcium-rich foods.
2. Limit your consumption of calcium supplements to avoid increasing your heart attack risk.
3. Discuss your specific daily calcium requirement with your physician: you may need less than previously thought. Although U.S. organizations currently recommend 1000-1200 mg daily, the British National Health Service, based on high quality research, recommends only 700 mg.
4. If your calcium intake must be supplemented to achieve your daily needs, evaluate which type of calcium is best for you.
5. Take at least 800 IU daily of Vitamin D3 in combination with adequate calcium intake. Have your physician check your Vitamin D blood level to ensure your level is adequate to promote strong bones and prevent fractures.
6. Eat dark, leafy greens for sufficient amounts of Vitamin K, which also promotes good bone health. Men need 120 mcg and women need 90 mcg daily.
7. Exercise for bone health. Weight-bearing exercise strengthens bones. Strength training improves balance and prevents falls that can cause fractures.
8. Avoid certain foods. Research suggests that excessive animal protein, coffee, cola soda, and high dose Vitamin A may weaken bones.