Calcium Supplements: When They’re a Good Idea and When They’re Not
Calcium supplementation for bone support has long held widespread acceptance from both the alternative and conventional medical communities based on the epidemic proportions of women that have osteoporosis or osteopenia. But less circulated is the valuable information that for calcium supplements to be safe and effective, they need other vital nutrients along with it. In fact, not getting these complementary nutrients can cause serious health complications.
The Good News About Calcium
Let’s first look at the portion of data that ties calcium intake to positive outcomes. Those who consumed an average daily dose of 820 mg of calcium per day from both food and supplement sources had a 30% reduced risk of heart attack. Increasing that dose to 1,100 mg from combined food and supplement sources did not create any greater risk reduction for heart attack than the 820 mg dose.
This is good news and supports previous data that suggest calcium intake can lower blood pressure, rates of type II diabetes and reduce heart attack risk. The really important point to note is that this is based on calcium consumption that is coming from both food and supplements combined. A balanced diet rich in calcium paired with some moderate supplementation seems to confer some benefits and shows no risk.
The Bad News (and Why It’s Not as Bad as It Looks)
The concerning data comes from a study that looked at the risk factors associated with getting calcium almost exclusively from calcium-only supplement sources. After all other factors had been adjusted for, those getting calcium primarily from supplements had double the risk for heart attack! The authors theorize that taking calcium supplements creates a sharp spike in calcium blood levels, whereas calcium from food sources creates a more stable elevation in calcium blood levels.
So, does this mean that your calcium supplements need to go in the trash or that you should stop taking all supplements with calcium in them? It absolutely does not. There are several factors that need to be considered.
It’s practically common knowledge that magnesium and calcium have an important relationship, however, many people don’t realize the importance of two other nutrients in this equation: Vitamin D3 and Vitamin K2.
Over the past 10 years, there has been a massive increase in awareness about the importance of getting adequate vitamin D, and as a result, many people are now using therapies that raise vitamin D levels. Increased blood levels of vitamin D will result in greater absorption of calcium in the blood. Although blood levels of vitamin D were not measured in study participants, it is possible that increased absorption of calcium due to better vitamin D status and increased rates of supplementation might have played a role in increasing heart attack risk.
Vitamin D is of the utmost importance for your body and it is critical to have optimal levels of this hormone-like compound (ideally blood levels between 45-65). As your blood levels of D increase, you may need less supplemental calcium, as your body can utilize more from food.
In my opinion, this is the most important part of the story. Increasing calcium intake and increasing blood levels of vitamin D will both result in more calcium in the blood, which, as the new study suggests, may be detrimental to our hearts. However, there is little talked about the vitamin that may very well be the key to this entire story.
Vitamin K2 activates two key proteins in the body that potentially reduce the risk of increased calcium intake having a detrimental impact on heart health.
The first protein is called osteocalcin and is produced in the bone by specialized cells charged with building bone called osteoblasts. This protein is essentially responsible for pulling calcium out of the blood and depositing it into the mineral matrix of bone tissue.
The second protein activated by vitamin K2 and critical to this conversation is called matrix gla-protein or often abbreviated MGP. It resides in many different places of the body but has a high concentration in the arterial walls. Research has demonstrated that its function in our blood vessels is to prevent the build up of calcium deposits. Essentially, it is our body’s protection mechanism to prevent calcium from being deposited into our arteries which protects them from hardening and calcification.
Human and animal studies have shown a clear correlation between under-active MGP due to vitamin K2 deficiency and increased risk of cardiovascular disease and death. A large scale human study called the Rotterdam Study showed that people with the highest dietary intake of vitamin K2 had a 50% reduced risk of aortic calcification and cardiovascular death than those with the lowest dietary intake.
As expected, Western diets are very deficient in vitamin K2 and although we typically get enough vitamin k to prevent bleeding disorders we don’t get enough K2 to optimally run these important proteins that regulate calcium deposition. This is exactly what we saw in the vitamin D story. Americans were getting enough to prevent rickets but not nearly enough to support optimal health. This makes vitamin K2 supplementation critical, particularly if people are also supplementing with calcium and D. Your body needs the tools necessary to appropriately manage all the extra calcium entering the blood stream as a result of enhanced absorption from the D and higher intake from the calcium supplements.
For years, I have recommended that everybody who takes vitamin D also take K2. The only exception would be someone taking the blood thinners warfarin or coumadin, which exert their action by blocking vitamin K1, but even those individuals can safely take K2 if monitored appropriately by a physician. Although K2 has less of an effect on the clotting cascade than K1, it is still an important consideration for those on warfarin or coumadin. A good vitamin D supplement should be formulated with some vitamin K2. This is an important thing to look for when choosing a D supplement.
Poor Study Design
The last part of this story is criticism that the study recently published is presenting bad data regarding calcium supplementation and cardiovascular risk. The main issue is that the study was not originally designed to look for cardiovascular risk and as a result, other risk factors for cardiovascular disease were not equally distributed across the study population. For example, the calcium supplement group that showed the increased rate of heart attack had a population of participants with a higher incidence of elevated cholesterol at baseline, and also included more smokers. These are certainly two significant risk factors that could have skewed the data. For a more detailed explanation, please visit the Council for Responsible Nutrition’s website.
The Bottom Line
Calcium has a long safety record with some noted benefits for the heart. However, this is the not the first study pointing to some possible risks and I think there is reason to be cautious. Getting your calcium from a combination of food and supplements is an important consideration and is not only logical, but also practical. Additionally, make sure to balance your nutrient intake of supplements that affect calcium absorption and distribution by using a combination of calcium, D and K2.
Dr. Passero completed four years of post-graduate medical education at the National College of Naturopathic Medicine in Portland, Oregon after receiving a Bachelor’s Degree in Environmental Biology from the University of Colorado. Dr. Passero has trained with some of the nation’s leading doctors in the field of natural medicine. In his practice, Dr. Passero focuses on restoring harmony to both the body and mind using advanced protocols that incorporate herbal therapy, homeopathy, vitamin therapy and nutritional programs. Through education and guidance patients are able to unlock the natural healing power contained within each one of us. For more information, visit his website, Green Healing Wellness, or follow him on Facebook.