Bone HealthThe skeleton is remarkable. It provides mobility, support, and protection for the body. It also serves to store minerals, such as calcium in the process of building bones. Bone is not a static organ, but constantly adapts to the internal environment of the body. The development of the bony skeleton likely began many eons ago, when animals left the calcium-rich ocean, first to live in fresh water where calcium was in short supply, and then on dry land where weight bearing put much greater stress on the skeleton. Bone architecture is comprised of two main components: minerals (calcium, phosphorous, magnesium) to give bone its strength, and connective tissue (collagen) to give bone some flexibility.
Minerals in bone are released when hormones in the body, such as parathyroid hormone (PTH), signal a need for increased blood levels of those elements. The body controls the level of calcium in the blood very closely, since it plays such a critical role in the health of all body organs, especially nerves and muscle. Vitamin D is actually a hormone that is crucial for bone health. It stimulates DNA in the intestines to produce more proteins that increase the amount of calcium that can be absorbed. Additionally, vitamin D acts to decrease the amount of calcium processed by the kidneys and eliminated from the body in urine.
Building BoneBone health is influenced by diet, exercise, dietary supplements, genetics, body size, habits (eg, smoking) and environmental contaminants. One of the largest determinants in bone health is the ability for the cells in the process of bone building to actively continue to break down old bone and produce new bone. There are two cells in bone responsible for building bones: osteoblasts and osteoclasts. An osteoblast (from the Greek “Osteo” meaning “bone” and “blast” meaning “germ” or “embryonic) create new bone and an osteoclast breaks down and recycles old bone.
This process of breaking down old bone and creating new bone is called “bone remodeling.” Osteoblasts come from osteoprogenitor cells located in the thin covering of the bone called the periosteum, and also in the bone marrow. Osteoprogenitor cells are immature cells that mature into osteoblasts when they receive specific chemical signals, such as growth factors. The primary growth factor appears to be bone morphogenetic proteins. However, other growth factors, such as fibroblast growth factor, platelet-derived growth factor, transforming growth factor beta (TFG-beta) may also be important for maturing osteoblasts, building bones and bone health.
Osteoclasts (from the Greek meaning “broken bone”) are actually derived from immune system cells called macrophages. An osteoclast is comparably much larger than an osteoblast and contains many nuclei. It also has many vacuoles, which are storage area within cells. When an osteoclast is actively breaking down bone it enlarges and creates a “ruffled border” appearance when looked at under a microscope. Hormones required for osteoclast formation include receptor activator of nuclear factor kappa beta (RANK) and macrophage colony-stimulating factor (M-CSF). Interestingly, these hormones are produced by osteoblasts, so there is constant communication between osteoblasts and osteoclasts, which work together to keep the bone remodeling process in a dynamic balance.
Many nutrients are important for bone health. Calcium and vitamin D are often the only nutrients people think about. However, calcium and vitamin D have only been shown to decrease fracture risk by about 18%. Additionally, calcium and vitamin D alone do not build bones, they merely slow down the rate of bone loss. Another nutrient that is too often overlooked is vitamin K. Many studies have shown vitamin K to be an important nutrient for bone health. Studies have tracked people’s eating habits over many years and concluded that the more vitamin K people eat through food, which is found in green leafy vegetables (kale, swiss chard, lettuce), the lower their osteoporosis risk.
Laboratory studies of vitamin K2 show that it inhibits osteoclast maturation and actually helps stimulate the destruction of osteoclasts, while simultaneously promoting osteoblast activity. Furthermore, additional studies suggest that vitamin K2 promotes the production of connective tissue in bone. Regular physical activity is important for bone health and reduces the risk of fractures. Like a healthy diet, adequate weight-bearing physical activity early in life is important in reaching peak bone mass.
Studies have confirmed the beneficial effects of exercise on bone health. Weight-bearing physical activities cause muscles and bones to work against gravity and stimulates bone production. Exercise can increase muscle mass, strength, and balance, thereby decreasing the risk for falling and suffering an osteoporotic fracture. Muscle strengthening and balance exercises (eg, Chi Gong, Tai Chi) have been shown to decrease risk for fall and fall-related injuries by 75% among women aged 75 years and older. In another study, one year of weight-bearing exercise training in community-living women (ages 66 to 87 years) improved hip bone mineral density by 8.4% compared to controls.
Examples of weight bearing physical activities include walking, jogging, running, tennis or racquetball, field hockey, stair climbing, jumping rope, basketball, dancing, hiking, soccer, and weight lifting.
Why Osteo-K clobbers the competition: click to view a chart comparing Osteo-K to other leading calcium supplements, such as Viactiv, Citracal, Bone-Up, Os-Cal and Caltrate.
You can also learn more by reading about MK7 and hip fracture.