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If you’re a fitness-minded person committed to an active lifestyle — regular exercise and activities that require mobility and strength — you probably think about your bones more than most people. After all, a broken bone represents a life-changing event for you. You’re going to be facing a lengthy interval of not being able to do the things you enjoy. In a general sense, just the physical act of exercising encourages you to consider the way your bones function and interact with each other.

And yet, you probably picture your bones in your mind in much the same way a sedentary person might. As inert, calcified masses that serve the purpose of shielding the vital organs and providing a scaffolding upon which muscles, tendons and ligaments can anchor themselves. To the extent that we think of bones as having active physiological properties, we think of the marrow inside bones, which produces white and red blood cells.

Emerging science, however, tells us that bones are doing so much more. Bones are, in fact, vital, living organs. They communicate constantly with muscle tissues and every organ of the body. They contain osteoblasts that secrete a hormone that may keep blood sugar levels in check and help us burn fat and build muscle, and appear to support brain function.

In essence, our bones are living secret lives that we are only just beginning to understand.

The Many Surprising Qualities of Osteocalcin

Bones, it turns out, are endocrine organs. Like your liver or pancreas, they secrete hormones that regulate bodily processes. While bones may in fact secrete a number of hormones, the one that has been the subject of most research up until now is osteocalcin, produced by osteoclasts in bone mass and once thought to be limited solely to the regulation of bone mineralization and re-formation.

Beginning in the 1990s, however, experiments that involved removing the gene for osteomycin production from mice resulted not in inferior bone formation but rather in the mice losing muscle, gaining fat, and being cognitively impaired. Researchers, led by Gerard Karsenty, a geneticist at Columbia University, began to pursue the ramifications of these findings. They genetically engineered one set of mice to produce higher amounts of osteocalcin and another set not to make it at all. When fed regular diets, the mice making extra osteocalcin had lower-than-normal blood glucose levels and higher insulin levels than regular mice. Insulin sensitivity increased as well. The osteocalcin-deficient mice, on the other hand, got fatter and tended to develop type 2 diabetes when fed a normal diet (1 Na Kyung Lee). They also tended to be more torpid and lethargic than normal mice.

Scientists have long known that bone loss (and muscle loss) accelerates as we grow older. They now recognize the production of osteocalcin inevitably decreases as we age as well. Subsequent investigations (by Karsenty and others) have begun to reveal that reduced osteocalcin production may have far-ranging negative effects on a variety of health and wellness markers. Karsenty and his colleagues have since collated the results of these investigations and published them in a highly influential overview of the metabolic functions of osteocalcin, in the journal Reviews in Endocrine and Metabolic Disorders (2 Jianwen Wei, Gerard Karsenty).

In summary, Karsenty theorizes that osteocalcin acts in muscle to increase the ability to produce ATP, the fuel that allows us to exercise. In the brain, it regulates the secretion of the neurotransmitters that support memory function. Circulating levels of osteocalcin decline in humans as they age, which is concurrent with declines in memory and the ability to exercise. Karsenty and his colleagues have begun to experiment with injecting older mice with osteocalcins. When the older mice receive supplemental osteocalcins, they appear to manifest evidence of improved memory and capacity for exercise.

Of course, this area of science is just evolving now and we're still some time away from osteocalcin therapy for humans. However, there are many well-indicated strategies for maximizing bone mass, health and its capacity for hormone production.

One is simply exercise. Scientists have long known that highly active people demonstrate consistently less bone loss, muscle mass decrease and cognitive decline as they age as compared to sedentary people. They have come to recognize that if you exercise regularly, that activity stimulates your bone to make more osteocalcin, which may have significant beneficial effects on muscle and brain function.

And then, too, nutrition plays an enormous role in bone health and function.

Vitamin D and Bone Health

Calcium is the most important nutrient for building bone and slowing the pace of bone loss. Calcium keeps bone material healthy and strong. Indeed, 99 percent of the body's calcium is stored in the bones and teeth. But just maintaining adequate calcium intake isn't enough to keep your bones healthy.

Your bones need Vitamin D to facilitate the absorption of calcium. Your body produces Vitamin D mostly by synthesizing it out of exposure to sunlight. It’s also available through diet from oily fish, beef liver, egg yolks and some Vitamin D fortified food sources like milk. Despite this, Vitamin D deficiency affects nearly half of the world's population and more than 40% of the US population. The reasons for this are many.


Most of us spend too much time indoors and even when we do go outside, we apply plenty of sunblock. Also, not everyone is fond of oily fish or beef liver. Even the angle of the sun comes into play. The best environment for Vitamin D synthesis is when the sun is directly overhead, as it is in the summer. In the winter, however, the sun is lower in the sky. Studies have concluded that ultraviolet light is inadequate for optimal vitamin D synthesis during at least a few months in winter in areas above 35 degrees latitude (which in the US runs through the southern borders of Tennessee and Nevada). For this reason, here in the US, our Vitamin D levels tend to peak in September and bottom out in March.

For these reasons, a high-quality Vitamin D supplement -- typically Vitamin D3, which is the most efficient form for elevating blood Vitamin D levels -- is well recommended. A couple of 1000-iu softgels or capsules daily can provide satisfactory support of Vitamin D levels, and larger doses may be even better for older people.

Synergy For Bone Health: Vitamin D3 and Vitamin K2

Some Vitamin D3 supplements, including ProSource's own superior-quality version, are combined with a synergistically viable dosage of Vitamin K. This fat-soluble substance is necessary for the production of prothrombin, a clotting factor essential for blood clotting and bone metabolism. Just as importantly, Vitamin K2 works in tandem with Vitamin D3 to enhance calcium uptake and utilization to help maintain bone density. It also helps to activate a key circulatory protein that inhibits blood vessel calcification.

Joint Health Goes Hand In Hand With Bone Health

Strong, healthy, vital bones are essential to overall well-being. So too is the health of the many ligaments, tendons and other connective tissues anchored to those bones. As is the case with bone fractures, one tear or strain to a tendon can be a life-altering event over an extended interval of time. Also like bones, the dense fibrous tissue of our tendons, ligaments, and cartilage can take a long time to heal. Fortunately, you can feed and strengthen joint tissue just as you would bone mass.

New supplemental technologies of joint support have come a long way in their capacity to maximize joint stability, flexibility, and strength. Glucosamine sulfate and chondroitin sulfate have been cited for their ability to facilitate the uptake of sulfur (a key building block of cartilage), support the production of friction-reducing synovial fluid, and help connective tissues retain water and remain flexible.


More advanced joint support supplements incorporate more recent validated science to keep connective tissue strong and vital. ProSource's own Extra-Strength Joint Command contains ultra-potent HyaMax™ as a primary ingredient. This natural, standardized hyaluronic acid possesses a unique water-retaining action to help highly active joints stay healthy. Joint Command also contains Meriva®, an advanced phytosome technology that enhances the bioavailability and anti-inflammatory properties of curcumin, as well as 5-LOXIN®, which contains the most active of the 6 boswellic acids, and AKBA, which helps inhibit 5-lipoxygenase, the compound responsible for the conversion of arachidonic acid into pro-inflammatory cytokines.


In order to manifest peak wellness and achieve your physique and performance goals, you have to build on a firm foundation. With regard to bones, that's always meant keeping them healthy, strong and sound to facilitate an active lifestyle. Now we know, however, that our bones have a lot more to offer. The more we learn about bones, the more we discover how interconnected they are with everything from muscle growth to brain function to a whole range of metabolic processes. Healthy bones are the key to a healthy life.

1 Na Kyung Lee, Hideaki Sowa, Eiichi Hinoi, Mathieu Ferron, Jong Deok Ahn, Cyrille Confavreux, Romain Dacquin, Patrick J Mee, Marc D McKee, Dae Young Jung, Zhiyou Zhang, Jason K Kim, Franck Mauvais-Jarvis, Patricia Ducy, Gerard Karsenty. Endocrine regulation of energy metabolism by the skeleton. Cell. 2007 Aug 10;130(3):456-69.

2 Jianwen Wei, Gerard Karsenty. An overview of the metabolic functions of osteocalcin. Rev Endocr Metab Disord. 2015 Jun; 16(2): 93–98.

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The articles featured herein are for informational purposes only and should not be construed as medical advice. Specific medical advice should only be obtained from a licensed health care professional. No liability is assumed by ProSource for any information herein.