Should We Take Calcium Supplements?

Written by Dr. Steve Chaney on . Posted in Calcium Supplements, Exercise, Food and Health, Healthy Lifestyle

Clearing Up The Calcium Confusion

Author: Dr. Stephen Chaney

should we take calcium supplementsShould we take calcium supplements?  You have every right to be confused about calcium supplementation. There have been a lot of conflicting headlines in recent months.

It has seemed like a no-brainer for years that calcium supplementation could help post-menopausal women and men over 50 avoid the debilitating effects of osteoporosis.

After all:

  • >99% of adults fail to get the USDA recommended 2.5-3 servings/day of dairy products.
  • 67% of women ages 19-50 and 90% of women over 50 fail to meet the RDA recommendations for calcium intake from diet alone.
  • Men do a little better (but only because we consume more food). 40% of men ages 19-50 and 80% of men over 50 fail to meet the RDA recommendations for calcium intake from diet alone.
  • Inadequate calcium intake over a lifetime is considered a major risk factor for osteoporosis.
  • Osteoporosis is serious business. It doesn’t just cause bone fractures. It can result in chronic pain, disability, long term nursing home care, and even death.

It’s no wonder that some experts have predicted that supplementation with calcium and vitamin D could save over $1 billion per year in health care cost savings. It is also why health professionals have recommended calcium supplementation for years, especially for postmenopausal women and men over 50.

However, recent headlines have claimed that calcium supplementation doesn’t really increase bone density or prevent osteoporosis (more about that later). Other headlines have suggested that calcium supplementation is actually bad for you. It may increase your risk of heart disease.

That’s why the general public, and even many doctors, are confused.  Should we take calcium supplements?  Everyone wants to know the answer to two questions:

  • Do calcium supplements work?
  • Are calcium supplements safe?

I will start with the second question first.

Are Calcium Supplements Safe?

are calcium supplements safeI have discussed the issue of calcium supplements and heart disease risk in a previous issue of Health Tips From the Professor. Briefly, the initial studies suggesting that calcium supplementation might increase the risk of heart attacks and cardiovascular disease were good studies, but they were small, short-term studies.

The initial studies raised an important question, so the scientific community stepped up to the plate and conducted larger, longer term studies to test the hypothesis. Both of those studies concluded that calcium supplementation posed no heart health risks.

Now a third major study on the subject has just been published (Raffield et al, Nutrition, Metabolism & Cardiovascular Disease, doi: 10.1016/j.numecd.2016.07.007). The study followed 6236 men and women ages 45-84 for an average of 10.3 years. The subjects were from four different race/ethnicity groups and came from 6 different locations in the United States. More importantly, there were 208 heart attacks and 641 diagnoses of cardiovascular disease during the study, so the sample size was large enough to accurately determine the relationship between calcium supplementation and heart disease.

The results were pretty straight forward:

  • The authors concluded: “[This study] does not support a substantial association of calcium supplement use with negative cardiovascular outcomes.” If you would like the plain-speak version of their conclusion, they were saying that they saw no increase in either heart attacks or overall cardiovascular disease in people taking calcium supplements.
  • If anything, they saw a slight decrease in heart attack risk in those taking calcium supplements, but this was not statistically significant.

In summary, the weight of evidence is pretty clear. Three major studies have now come to the same conclusion: Calcium supplementation does not increase the risk of either heart attacks or cardiovascular disease.

Of course, once information has been placed on the internet, it tends to stay there for a very long time – even if subsequent studies have proven it to be wrong. So the myth that calcium supplementation increases heart attack risk will probably be with us for a while.

So, should we take calcium supplements?  Let’s first investigate a little further.

 

Do Calcium Supplements Work?

do calcium supplements workAs I mention above, recent headlines have also suggested that calcium supplementation does not increase bone density, so it is unlikely to protect against osteoporosis. I analyzed the study behind those headlines in great detail in two previous issues of Health Tips From the Professor.

In Part 1 Calcium Supplements Prevent Bone Fractures  I pointed out the multiple weaknesses in the study that make it impossible to draw a meaningful conclusion from the data.

 

In Part 2 Preventing Osteoporosis  I discussed the conclusion that the study should have come to, namely: Adequate calcium intake is absolutely essential for strong bones, but calcium intake is only one component of a bone healthy lifestyle.

The bottom line is that calcium supplementation will be of little use if:

  • You aren’t getting adequate amounts of vitamin D and all of the other nutrients needed for bone formation from diet and supplementation.
  • You aren’t getting enough exercise to stimulate bone formation.
  • You are consuming bone dissolving foods or taking bone dissolving drugs.

Conversely, none of the other aspects of a bone healthy lifestyle matter if you aren’t getting enough calcium from diet and supplementation.

The bottom line is that you need to get adequate calcium and have a bone healthy lifestyle to build strong bones and prevent osteoporosis, and calcium supplementation is often essential to make sure you are getting adequate calcium.

 

Should We Take Calcium Supplements?

should we take calcium supplements nowShould we take calcium supplements?  If you are one of the millions of Americans who aren’t meeting the RDA guidelines for calcium from diet alone, the answer is an unqualified yes.  Calcium supplementation is safe, and it is cheap.  Osteoporosis is preventable, and it is not a disease to be trifled with.

However, you also need to be aware that calcium supplementation alone is unlikely to be effective unless you follow a bone healthy lifestyle of diet, exercise and appropriate supplementation to make sure you are getting all of the nutrients needed for bone formation.

Of course, it is always possible to get too much of a good thing. The RDA for calcium is 1,000 – 1,200 mg/day. The suggested upper limit (UL) for calcium is 2,000 – 3,000 mg/day.  I would aim closer to the RDA than the UL unless higher intakes are recommended by your health care professional.

 

The Bottom Line

 

  • 80% of men and 90% percent of women over 50 do not get enough calcium from their diet.
  • Consequently, doctors have consistently recommended calcium supplementation to prevent osteoporosis, and 50% of men and 60% of women over 60 currently consume calcium supplements on a regular basis.
  • Some small, short term studies suggested that calcium supplementation might increase the risk of heart disease, and warnings about calcium supplementation have been widely circulated on the internet. This hypothesis has been evaluated by three larger, longer term studies that have all concluded that calcium supplementation does not increase heart disease risk.
  • A recent study claimed that calcium supplementation was ineffective at increasing bone density, and that report has also been widely circulated. However, there are multiple weaknesses in the study that make it impossible to draw a meaningful conclusion from the data.
  • If you are one of the millions of Americans who aren’t meeting the RDA guidelines for calcium from diet alone, you should consider calcium supplementation.  It is safe.  It is effective when combined with a bone healthy lifestyle of diet, exercise, and appropriate supplementation.  Finally, it is cheap. Osteoporosis is preventable, and it is not a disease to be trifled with.
  • Of course, it is always possible to get too much of a good thing. The RDA for calcium is 1,000 – 1,200 mg/day. The suggested upper limit (UL) for calcium is 2,000 – 3,000 mg/day. I would aim closer to the RDA than the UL unless higher intakes are recommended by your health care professional.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (6)

  • Jennifer

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    Calcium supplements were the wrong thing for me, I recently learned. I am hyperparathyroid, due to a tumor on one or more parathyroid glands. The calcium level in my blood had risen to 12.5 due to the malfunction of the parathyroid gland that regulates calcium in the bones, and more. I had osteoporosis—so all the more reason to take calcium? Wrong. For years, I faithfully took calcium, until this year. For years, doctors mused over my high blood calcium levels, above 10. However, due to thinning bones, every one recommended calcium supplements. Now that the tumor and malfunction is discovered, I halted all calcium and I’m preparing for surgery to remove the tumor(s) on my parathyroid gland(s), the only cure. One should not assume that thin bones are the only marker to take calcium.

    Reply

    • Dr. Steve Chaney

      |

      Dear Jennifer,
      You are correct in saying that calcium supplements won’t help if you are hyperparathyroid. However, I must wonder how your doctor’s missed that diagnosis. With thinning bones and high blood calcium levels, they should have tested you for hyperparathyroidism – not muse about it.
      Dr. Chaney

      Reply

  • Jeanie Porter

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    Dr. Chaney, I would like additional information on where magnesium fits into the calcium/osteoporosis equation and in what ratio it should be included. Also, the same for strontium – how important is it for bone health and in what ratio?
    Thank you. Jeanie Porter

    Reply

    • Dr. Steve Chaney

      |

      Dear Jeanie,
      You should certainly aim for RDA intake of magnesium (300-310 mg/day for women and 400-420 mg/day for men. I have seen recommendations for a 2:1 ratio of calcium to magnesium. What many people neglect to say is that holds only up to RDA levels of calcium (which would correspond to 400-500 mg/day of magnesium. It is also important to know that excess magnesium can cause diarrhea. If you are taking a magnesium supplement, you get one that is sustained release.
      Strontium is more complicated. There is a form, strontium ranelate, that is prescribed to help increase bone density in women with osteoporosis in Europe. However, it has not been approved for use in this country, and the strontium supplements used in this country are unrelated to strontium ranelate. Unfortunately, there has been very little research on strontium supplements in this country. In short, strontium supplements may help increase bone density, but we have no idea what kind or how much would be beneficial.
      Dr. Chaney

      Reply

  • Ruth wood

    |

    Hello Dr. Chaney.
    I’m interested in information regarding the effect of calcium supplementation on development of kidney stones.

    Reply

    • Dr. Steve Chaney

      |

      Dear Ruth,
      Some forms of kidney stones do contain calcium, but if your calcium intake is less than 4,000 mg/day, the kidney stones are probably not caused by excess calcium. Kidney stones are more likely caused by inadequate water intake, too little magnesium, too little B6, too much vitamin D, or hormone imbalances. If you are getting adequate water, magnesium, and B vitamins and still suffer from recurrent kidney stones, you should probably get a full workup by your physician.
      Dr. Chaney

      Reply

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Latest Article

A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

For more details read the article above.

 

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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