To Calcium or Not to Calcium?

Two big studies that came out recently have muddied the waters on the one nutritional supplement that even conventional medicine has rallied behind:  calcium.

We've all heard that supplemental calcium is good for the bones, and may even protect against colon cancer in older adults.  Seems like a logical recommendation.  But like hormone replacement therapy, whose cardiovascular benefits were disproven ten years ago by the Women's Health Initiative study, calcium supplements are now being called into question.

The first chink in the armor came a few weeks ago when a study sponsored by the National Institutes of Health (NIH) (1) found that supplemental calcium boosts the risk of death by cardiovascular disease (CVD) in men, but not women.  Men who consumed 1000 mg/day of calcium supplement had a 20% higher risk of CVD death than those who took no calcium.

OK, great... men, ditch the calcium; women, keep popping those ginormous horse pills.  Until February 13, when BMJ (British Medical Journal) (2) published the findings of Swedish scientists, who found that calcium supplements increased death rates in women, too.  Examining the findings more closely, though, we find some important details:  the all-cause mortality rates were doubled in women with a calcium intake of  more than 1400 mg/day, compared to those getting 600-1000 mg/day.  A further complication is that risk of death was increased if the calcium came from supplements rather than food.

The US Preventive Services Task Force (3) has also chimed in, with a re-analysis of older data that showed that 400 IU of vitamin D plus 1000 mg of calcium per day did not significantly prevent fractures in healthy older women.

These studies add more weight to hints that have been accumulating over the years, that just increasing calcium intake is not necessarily better for health.  Some cultures of the world have very low levels of calcium intake, but very little osteoporosis.  Meanwhile, the US recommendations for daily calcium have climbed over the years, so that now the RDA for women over age 50 is 1200 mg/day.  When it comes to bone health, just adding more calcium is like throwing more bricks on a construction site, and hoping that they'll form a building.  You also need an architect and foreman -- namely, vitamin D and vitamin K.

So how do we parse all this confusion about calcium, health, and disease for older adults?  Here's my bottom line:

• Men:  Keep your daily calcium intake under 1000 mg/day.  For most men, this means skipping the calcium supplements altogether.
• Women:  Ditch the high-dose calcium supplements that provide 1000-1500 mg/day.  Aim for that 600-1000 mg/day range total between dietary and supplemental calcium, with an emphasis on dietary sources (dairy, leafy greens, sardines).
• Men and women:  Get your blood tested for 25-hydroxyvitamin D on a regular basis; aim for a level between 40-80 ng/ml.  If it is low, you may safely take higher levels of supplemental vitamin D3 (consult your doctor for the right amount -- I usually recommend anywhere from 2,000-10,000 IU per day).  If you have CVD, osteoporosis, or risk factors for these conditions, be sure to get extra vitamin K along with vitamin D3.

Stay tuned; like all of nutritional science, the landscape and recommendations are constantly in flux.

1.  Xiao Q, Murphy RA, Houston DK, Harris TB, Chow WH, Park Y. Dietary and supplemental calcium intake and cardiovascular disease mortality. JAMA Intern Med 2013; DOI:10.1001/jamainternmed.2013.3283. 

2.  Long term calcium intake and rates of all cause and cardiovascular mortality: community based prospective longitudinal cohort study.  BMJ 2013; 346 doi: http://dx.doi.org/10.1136/bmj.f228 (Published 13 February 2013)

3.  

Vitamin D and Calcium Supplementation to Prevent Fractures in Adults: U.S. Preventive Services Task Force Recommendation Statement.  Ann Intern Med. 26 February 2013

Is Vitamin D Good for the Heart or Not?

Based on much recent research linking low levels of vitamin D to increased risk of heart disease, this is something I measure in all of my older patients.  If low, supplementation is simple, cheap, and can effectively raise those levels back up.  This is especially important at this time of year, since the sun is not strong enough to produce any vitamin D from skin exposure at our latitude.

A recent study in the Journal of Clinical Endocrinology & Metabolism (1) looked at the question of whether or not supplementing with vitamin D can change cardiovascular risk.  This was one of the first actual placebo-controlled clinical trials to examine the question.  Half the participants got vitamin D3 (a good quality form of vitamin D), and the other half got placebo.  At the end of the study, they examined cardiovascular risk markers, such as blood cholesterol, blood pressure, and C-reactive protein, and found no significant difference between the groups.  The conclusion?  Quoting from the New York Times:

“The study actually shows that vitamin D does not protect you against heart disease,” said Helen M. Macdonald, a senior lecturer at the University of Aberdeen in Scotland, who led the study. “That’s not what people want to hear, but it’s true.”

Now hold on a minute.  The researchers are making a huge assumption:  that the risk markers of cholesterol, C-reactive protein, etc., are synonymous with heart disease.  The thinking is that if something (in this case vitamin D) does not affect those traditional risk markers directly, there is no impact on heart disease.   However, it is well known that a significant percentage of heart disease and heart attacks occur in people with normal cholesterol levels and blood pressure.  Perhaps vitamin D is an independent risk factor -- that is, it could protect against heart disease without changing those other parameters.

The way to  really tell this for sure experimentally would be to use actual cases of heart disease as the end point of vitamin D supplementation.  This study was a good first step, but the error in logic on the part of the researchers is glaring.  In the meantime, I'll keep checking blood levels of vitamin D on my patients over age 40 as part of an overall cardiovascular risk assessment, using the naturopathic principle of "Treat the whole person."

1.  Vitamin D₃ Supplementation Has No Effect on Conventional Cardiovascular Risk Factors: A Parallel-Group, Double-Blind, Placebo-Controlled RCT.  Published online before printAugust 3, 2012, doi:10.1210/jc.2012-2126
The Journal of Clinical Endocrinology & Metabolism, October 1, 2012 vol. 97 no. 103557-3568

Top 5 "Myths" in Natural Medicine

As a doctor of naturopathic medicine, I have years of experience and training to respect the vis medicatrix naturae, or healing power of nature.  This is foundational to our approach to health.  I also have a background in science, and know that it is important to examine natural methods of health care to see if they are valid and effective.

That is why (though it might be dangerous to step on some toes) I like to clarify common misperceptions:  My goal is to help patients be as healthy as possible, not to be wedded to a particular idea.  Therefore, over the next few articles, I will present five common myths I often encounter, in no particular order.

Myth #1: Policosanol is a good alternative to cholesterol-lowering medication.
Policosanol is an extract of the sugar cane plant that made big news about ten years ago, with studies showing it was very effective at lowering blood cholesterol levels (1).  The nutritional supplement industry responded with a deluge of policosanol products.  However, much of that early research was conducted in Cuba, the source of the sugar cane--the raw material for policosanol production.  Follow-up studies conducted on larger populations, showed little to no clinically significant cholesterol-lowering effects of policosanol (2, 3).  Even though this well-designed research was published in 2006, policosanol sales continue to this day.  More recent research from 2011 (4) found that even a form of policosanol modified to make it better absorbed from the gastrointestinal tract failed to make a significant dent in cholesterol levels.  Some recent studies showing benefits used policosanol in combination with red yeast rice and berberine, two natural compounds that have been proven time and again to be effective in lowering cholesterol.  It's highly likely in these studies that the policosanol could have been left out, without affecting the results.

With all this evidence against policosanol, why are sales still so brisk today?  Well, in the midst of bashing the evil of Big Pharma companies, we sometimes forget that supplement companies are businesses, too, driven by market forces.  As long as there's a demand for policosanol (based on those biased studies from 10-15 years ago), they'll keep selling it.  Sorry, folks--supplement companies are not selfless crusaders for health; they're driven by the profit motive.  It's the American way.

I stopped recommending policosanol in 2006, in favor of much more effective treatments.  I also like to remind patients that high cholesterol is not a disease; it's a risk factor for cardiovascular disease (CVD).  I put the emphasis on lifestyle factors for CVD prevention, and look at modifying other risk factors too (such as high-sensitivity C-reactive protein and blood levels of vitamin D).

Next Time:  Cinnamon for blood sugar control

1.  Policosanol: a new treatment for cardiovascular disease?  Altern Med Rev. 2002 Jun;7(3):203-17.

2.  Effect of policosanol on lipid levels among patients with hypercholesterolemia or combined hyperlipidemia: a randomized controlled trial.  JAMA. 2006 May 17;295(19):2262-9.

3.  Comparative lipid-lowering effects of policosanol and atorvastatin: a randomized, parallel, double-blind, placebo-controlled trial.  Am Heart J. 2006 Nov;152(5):982.e1-5.

4.  Modified-policosanol does not reduce plasma lipoproteins in hyperlipidemic patients when used alone or in combination with statin therapy.  Lipids. 2011 Oct;46(10):923-9. Epub 2011 Jul 8.

Transitions

It's that time of year.

Yes, the weather is still blazing summer heat (though we've finally been getting a break now and then!), but we hit a transition in the last couple of weeks.  Somewhere in there, we reached the point where it's still dark outside when my 5:30am alarm goes off.  There's about a three-month period -- six weeks on either side of the summer solstice -- when I get to awake to glorious dawn light.  It's a natural part of our physiology:  It's much easier to get up and get started on the day that way, than to feel like my alarm is going off in nighttime darkness.

So this is my reminder that we're starting on the back half of the year, approaching autumn, sliding gradually toward the winter solstice, the days becoming shorter and shorter.  We're even getting back into the school year routine.

As we approach this transition, it's a good time to reflect on our health habits.

• I get energized in the early morning darkness with a contrast shower (most important as the weather gets cooler).  
• Take an inventory of your eating habits:  Did you take advantage of the abundant fresh fruits of summer, or use the hot weather as an excuse to indulge in too much ice cream, barbecue, and diet soda?  Reorient your thinking to the rich fall harvest of healthy veggies and lean meats.  
• As the days get shorter, it's also a time to think about getting your blood levels of vitamin D tested, since low levels of this "sunshine vitamin" have been associated with cardiovascular disease, autoimmune disease, seasonal affective disorder, and polycystic ovarian syndrome, to name a few.  
• And if the summer led to relaxation of your exercise routine, time to get back into some physical activity, since it's so critical to your health.

Even as we still enjoy the summer warmth, start thinking ahead to make the rest of the year vibrantly healthy.