Search results for calcium

What’s the latest on calcium supplements?

Posted by Liz on Jan 3, 2014 in Boomer | 0 comments

Calcium. Lord knows that both men and women need calcium for bone health. However, women in particular start to lose bone density as early as age 35 and, within the first 10 years of the onset of menopause, up to 50% of spongy, or trabecular bone (the network that makes up most of bone structure) and up to 30% of cortical bone (the outer shell) are also lost.

Despite its importance to bone health, there is a lot of controversy surrounding calcium, particularly when it comes to the recommended dietary allowance or RDA.  Currently, the Institute of Medicine recommends that women between the ages of 19 and 50 ingest at least 1,000 mg a day and those over 50, 1,200 mg a day. Still, too much of a good thing is too much; an overreliance on supplementation (often as a result to avoid milk, yogurt, cheese and other dairy products) may increase the risk for heart disease and kidney stones.

In a review in the journal  Menopause, researchers note that women who rely on supplements for their daily calcium needs more often than not take doses that exceed the RDA. The reason that this is problematic is that our bodies cannot absorb more than 500 mg daily of calcium from either food or supplements in any two-hour period, so if you are eating calcium rich foods (which in addition to the aforementioned dairy also includes canned fish with bones, tofu, calcium-fortified products, broccoli, collards and kale), also adding a daily supplement may take you to a place that you want to avoid. Importantly, while higher dietary calcium from food actually appears to reduce kidney stone formation and may even offer protection from heart disease, the opposite is true for supplements:

• In the Women’s Health Initiative study, exceedingly high intake of calcium (from a combination of diet and supplements) was shown to increase the risk for kidney stones by 17%.
• While the link between calcium supplements and heart disease is still being teased out, findings from a large review concluded that they raised the risk for heart attack by as much as 30%.

What should you do?

• Obtain as much calcium as you can from your diet to meet recommended daily goals and only take supplements if this is impossible or if recommended by your health practitioners.
• Contrary to popular belief, the RDA goal for calcium can often be reached by taking only 500 mg daily of calcium via supplement.
• If you are going to rely on calcium supplements, form matters. Researchers believe that calcium citrate may be less likely to cause kidney stones than calcium carbonate. And as I wrote back in 2009, there may be an advantage to a form of calcium known as ossein-hydroxyapatite complex (OHC), which is the mineral component of bones and teeth (OHC goes by the brand name of MCHA or MCHC and is easily found on the web).

Calcium, vitamin D and heart disease. What’s the 4-11?

Posted by Liz on May 2, 2011 in bone health, heart disease | 5 comments

“Calcium supplements cause heart attacks in postmenopausal women.”

Whoa! What?!

If you saw the headlines last week, you may be wondering what’s up with calcium supplementation. Afterall, don’t medical professionals advise the use of supplements to stave off bone loss associated with osteoporosis? And as a result, the Centers for Disease Control reports that over 50% of adults currently use calcium supplements and more than 60% of women over age 60.

It’s important to get away from the sensational headline and take a closer look at what the research shows and what you need to know.

Previous studies have suggested that there may be a link between use of calcium supplements (without vitamin D) and heart attack; in fact, as Reuters‘ reported last year, calcium supplements were shown to increase the risk of heart attack by as much as 31%, possibly as a result of plaque formation in blood vessels. However, is the risk the same if calcium is used alone versus if it is used in conjunction with vitamin D?  In the Women’s Health Initiative study, the use of calcium and vitamin D did not appear to influence heart disease risk at all.

However, researchers decided to take another look at the data because they say that in this trial, more than half of participants were taking ‘personal calcium’ (i.e. not regulated or standardized to all trial participants) and almost half were also adding Vitamin D.

In this reanalysis, published just last week in the British Medical Journal, the researchers discounted the women who were characterized as personal users of calcium supplements and instead, limited their evaluation to a group of women who were not using personal calcium supplements at the study’s start and previously unpublished data from the trial. The findings? The use of calcium with or without vitamin D appeared to cause a 25% to 30% increase in the risk for heart attack and a 15% to 20% increased risk for stroke. However, the researchers say that even small increases in the incidence in heart disease may manifest substantially, especially in the elderly. They add that if you take a look at the risk-benefit ratio, it is unfavourable, meaning that taking calcium with or without vitamin D for five years would cause twice as many heart attacks or strokes than then numbers of fractures that would be prevented.  Additionally, the data analysis suggests that dosing is not a factor, and that the total amount of calcium taken daily is less important than the abrupt changes in blood calcium levels immediately following supplementation.

Although this research answers a few questions about potential risks about calcium supplementation, it also leaves a key question unanswered:  how does the addition of magnesium and vitamin K, which are often included in commercially-available calcium supplements, affect these findings? Data suggest that these minerals and vitamins are added to keep calcium in the bones where it belongs and out the arteries where it does not.

The best guideline, as always, is to visit a physician to assess your bone health and come up with a plan that works specifically for you. Although calcium supplementation appears to be risky, more data are needed before leading organizations start to change their tune about calcium and bone health. Meanwhile, stay ahead of the headlines and try to focus on increasing the amount of calcium-rich foods in your diet:

* DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents among products within the context of a total daily diet. The DV for calcium is 1,000 mg for adults and children aged 4 years and older. Foods providing 20% of more of the DV are considered to be high sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet. The U.S. Department of Agriculture’s Nutrient Database Web site lists the nutrient content of many foods. It also provides a comprehensive list of foods containing calcium.
** Calcium content varies slightly by fat content; the more fat, the less calcium the food contains.
*** Calcium content is for tofu processed with a calcium salt. Tofu processed with other salts does not provide significant amounts of calcium.

When it comes to calcium, think moderation

Posted by Liz on Jun 4, 2010 in bone health | 3 comments

There’s a new condition emerging among postmenopausal women: calcium alkali syndrome (milk-alkali syndrome).

Milk calcium what?!

A wonderful commentary slated to appear online this month in the Journal of  the American Society of Nephrology highlights the dangers of consuming too much calcium . In it, the author  tells the tale of Chicago bartender Bertram Welton Sippy, who in 1915, introduced his bar patrons with ulcers to the Sippy diet, hourly intake of milk, cream eggs and farina cereal interspersed with Sippy powders on the half hour (i.e. dissolvable antacid like minerals that included calcinated magnesia, sodium bicarbonate and bismuth subcarbonate). A recipe for disaster? You bet, because the overkill of calcium and minerals led to symptoms that include headache, nausea, vomiting, mental clouding, a distaste for milk and eventually, kidney failure. Yikes!

While men were the primary victims of the condition in the last century, it appears that a new group of victims started to emerge in the 90s – postmenopausal women who have increased their intake of calcium and vitamin D to combat osteoporosis. And although calcium, not milk, is the primary driver, the condition is the third most common cause of hospital admission for significantly elevated blood calcium levels.

It appears that the necessity to preserve our bones has created a modern version of the Sippy diet.

The best strategy for reducing the risk of calcium-alkali syndrome is to moderate your intake of calcium supplements. In fact, the authors say that although an average of more than 4 g/day of supplemental calcium is most commonly linked to illness, small numbers of women have developed it on as little as 1 to 1.5 g calcium a day. Of note, while younger adults are able to store excess calcium in bone, aging seems to reduce this natural defense and instead, calcium tends to leave the bone (thereby leaving us more susceptible to fragile bones and osteoporosis) and in turn, a potential build up in the bloodstream. Still, the authors emphasize that calcium supplements in moderation are a necessary and beneficial option for women at risk for osteoporosis. The trick is to limit supplemental calcium intake to no more than 1.2  to 1.5 grams daily because our bones need protection. Read the label. And speak to your healthcare practitioner. When it comes to protecting our bones through supplementation, moderation appears to be the key.

p.s. Stay away from the Sippy diet. It’s a sippier slope (sorry, couldn’t resist!).

Calcium conundrum: which supplement should I choose?

Posted by Liz on Sep 18, 2009 in bone health | 0 comments

Calcium supplements come in many forms including calcium citrate,  calcium carbonate and calcium gluconate.  Experts have long said that when it comes to selecting a calcium supplement, type is less important than the amount of calcium that is available for absorption by the body. This can be determined by looking at % of the recommended daily amount that is available in each dose. Currently, the National Osteoporosis Foundation recommends that women between the ages of 19 and 49 ingest 1,000 mg daily and over age 50, 1,200 mg daily.

Hence, I was intrigued when I ran across a newly published review in the September/October issue of Menopause that shows a significant advantage with a form of calcium I had not heard of before: ossein-hydroxyapatite complex (OHC), which is the mineral component of bones and teeth.

Conducting an extensive review of six clinical trials that compared OHC to calcium carbonate in 614 postmenopausal women, the researchers found that OHC was statistically superior to calcium carbonate in terms of preventing bone loss and increasing bone mineral density (BMD). Importantly, use of vitamin D did not affect the results nor did further statistical analyses.

OHC is available in microcrystalline form and often goes by the name MCHA or MCHC. This helps insure adequate absorption by the body. I’ve seen it available online and its price structure is similar to other standardized supplement formulations.

After menopause, women can experience as much as a 30% loss of bone, thereby increasing the risk for osteoporosis. I am heartened by this research and by the fact that we now have another tool in our kit to keep our bones strong and healthy. Prevention is key!

A new equation for midlife: calcium+vitamin D+physical activity+better eating =

Posted by Liz on Jan 16, 2009 in health, general, weight | 1 comment

Weight gain. Data abound that show that women between the ages of 50 and 79 experience age-related changes in body composition, metabolism, and hormones, often accompanied by a decline in physical activity. This leads to a propensity for fat and weight gain.

Okay, so that’s the not-so-good news.

The good news is that daily calcium (1000 mg) plus 400 IU of vitamin D may have a small effect on the risk of weight gain. Even better, coupled with other dietary and lifestyle changes (nutrition counseling, physical activity), weight gain may be a thing of the past, or at least, something that is a lot more controllable than we think!

In one study, 36,282 women who were already participating in the Women’s Health Initiative trial and undergoing dietary modification or hormone replacement therapy were assigned to 1000 mg calcium plus 400 IU vitamin D or placebo daily. Weight and height were measured annually for seven years.

Study results, which were published in the May 2007 edition of Archives of Internal Medicine, suggest that women taking daily calcium plus vitamin D supplementation were 11% less likely to experience  modest weight gain (2 to 6 pounds) and also 11% less likely to gain more than 6 pounds. Interestingly, a reduced risk was seen in women who were ingesting less than 1,200 mg calcium daily, which is the recommended daily amount (RDA) by the Food and Nutrition Board of the National Academy of Sciences. Notably, the researchers do caution that the findings do not alter the RDA and that women should still aim for the 1,200 mg daily RDA of calcium.

In a second, more recent study published in the online edition of  Maturitas, 101 postmenopausal women were assigned to dietary intervention (1200 mg calcium plus .75 mc vitamin D plus fortified dairy products daily), 1200 calcium daily or placebo. Women in the dietary intervention also attended biweekly dietary and lifestyle intervention sessions.

Similar to results of the first study, women receiving dietary interventions had significantly lower increases in skin thickness measures and experience declines in fat mass compared to the other two groups.

In concert, these results suggest that daily intake of calcium plus vitamin D, coupled with dietary restrictions and physical activity, may help to stave off the extra pounds in midlife. As with any regimen, it is essential to discuss a new regimen with your healthcare practitioner before taking the leap.

I’ve written previously about the value of calcium, dietary restrictions and physical activity to overall health, preventing osteoporosis and heart disease, and lowering the risk of weight gain. The addition of vitamin D appears to make the equation even more effective.

Although there have been many articles written of late that tout the benefits of vitamin D, like anything, it’s not the panacea for all that ails. Good health starts with thoughtful, well-informed choices. But it’s inspiring to know that there are positive steps you can take to feel good and look even better!