Strengthening bones through bioavailability
By Jeff Leach

Osteoporosis. Just saying the word makes my bones ache. If you’re a woman over the age of 50, you have about 40% chance of suffering from an osteoporotic fracture. That’s higher than your risk of contracting breast and ovarian cancer. Even worse, 50% of the osteoporotic hip-fracture patients never fully regain independence and more than 20% will die within 6 months. Not good odds.

If you are someone who thinks osteoporosis is a “women’s disease,” think again. It affects 25% of men over the age of 50 and an alarming number of young people. If the current trends continue, the problem is expected to worsen by 60% in the next 20 years – regardless of gender.

Most folks are aware that osteoporosis is characterized by bone fragility and related to dietary intake of calcium, or the lack thereof. Simply put – calcium is used to build bones and to a lesser extent, teeth. From the time we are born until our mid twenties, our bones are continually growing and require calcium to do so. The goal during this critical growth period is to achieve peak bone mass. Thick, mineral dense bones.

Your peak bone mass – which again, you can only control until your mid twenties – will strongly influence your risk of osteoporosis later in life.

From our mid twenties to about age 50, the density of our bones is relatively stable. This means no matter how much calcium you consume, your bones are not going to get any denser. The goal now is to maintain the bone mass you developed in youth and minimize bone loss associated with aging. This is especially important for women, who must contend with a number of bone loss issues exaggerated during and after menopause – not to mention the demands of pregnancy and lactation on bone health.

While you are older and wiser, the efficiency at which your body absorbs calcium in later years, like some many things associated with aging, isn’t what it used to be.

Despite the fact that we are confronted daily with the “eat more calcium” message for “healthy bones” on TV, in newspapers and magazines, on annoying billboards, and along the aisles of our favorite grocery store, nearly 70% of Americans consume less than the daily recommended allowance of  1,000 mg of calcium a day – give or take.

Our daily intake may in fact be lower when you consider that, depending on our particular genetic makeup and the composition of a given meal, our bodies may only absorb 30-35% of the total calcium advertised for a given serving. Think about that little piece of critical information for a minute.

Calcium that is not absorbed is mostly excreted in our urine and feces, which brings up an important issue – and the point of why I am writing about osteoporosis – bioavailability.

The terms “bioavailability” and “absorption” are critical nutritional terms that are often used incorrectly. Absorption describes the process of transport of a mineral-like calcium from your intestine across the intestinal mucosa (the wall) into the circulatory system, so that it may be utilized or stored by the body. On the other hand, the bioavailability of a mineral like calcium means the “proportion” that is actually absorbed and thus utilized or stored.

The key here is solubility. A swallowed penny, for example, has zero bioavailability. It will simply enter one end and come out the other, intact. Whereas a glass of water is highly soluble and will be easily absorbed – nearly 100% bioavailability.

Even though you think you are getting 500 to 1,000 mg of calcium from a given food item, meal, or “supplement,” you may not.

Given this piece of information, it’s not only important that we increase our daily intake of calcium to recommended levels, we should also seek out means to increase the bioavailability of the calcium that we do consume so that it’s not wasted, so to speak.

One way of doing this is to lower the pH of your gastrointestinal system by delivering food to the trillions of tiny bacteria that live in your colon (specifically lactic acid bacteria). And that means fiber. 

Once in the colon, fiber is broken down by resident bacteria through hydrolysis and fermentation, which produces, among other things, short chain fatty acids and lactic acid. These acids then in turn make the colon more acidic, which increases the solubility of the calcium, making it more absorbable.[1] One of the short chain fatty acids produced (butyrate) has been shown to induce cell growth in the colon, which in turn increases the “absorptive surface” of the colon. This means more calcium is absorbed and less is excreted in feces.  

Among the hundreds of species of bacteria living in your colon, you want to increase the number of the bifidobacteria and lactobacillus, specifically. These two particular groups are known to be especially useful in increasing the acidity of your colon – and they thrive well on special inulin and oligofructose-type fibers that occur naturally in onions, garlic, artichokes, asparagus, and in lesser amounts in wheat-based products. They are also commercially extracted from chicory roots (think chicory coffee) and added as a food ingredient in a growing number of foods. These special fibers are known as prebiotics.

By increasing the bioavailability of the calcium that we do consume through a more acidic colon, we can add an additional dietary measure to the preventive strategies for fighting this terrible disease.

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