Zinc can do more to prevent brittle bones than any other nutrient. Collagen tissue is necessary for the deposition of calcium phosphate to form bone. That is, collagen tissue provides the infrastructure for bone to form. It is in this structure that calcium is deposited to form bone. The presence of collagen is essential for the strength and density of the bones. Without it, all the calcium in your diet has nowhere to go, and zinc is an essential part of collagen formation.
Collagen holds it all together.
Collagen is the most widespread tissue in the body. It forms the bottom of all your tissues and all your organs, making them firm and resistant. When skin begins to wrinkle and lose elasticity, you can be sure your collagen cells aren’t as active as they used to be.
Each strand of collagen is made up of amino acids, and many of these amino acids are needed to form a strand. The strength of collagen tissue increases as some of the molecules are strengthened through a biochemical process initiated by vitamin C. This process helps stabilize the entire collagen structure. If the process does not occur, the bones soften. Initially, three single strands of collagen are coiled around each other, forming a triplet. Three of these triplets are then coiled around each other to form a super cable. Each strand is also linked to adjacent strands by crosslinking. It is in this collagen structure that calcium phosphate is deposited to form bones. Therefore, bone is made up of collagen (an organic protein – living material) and calcium phosphate (an inorganic material).
Collagen slowly ages to be replaced by new collagen tissue. To ensure that this process continues, it is important to ensure that protein and nutrient intake is adequate. One of the important nutrients is zinc.
Zinc a critical nutrient
Adequate levels of zinc are necessary to form collagen tissue, bridge bone fractures, heal wounds, and prevent osteoporosis. For the formation of collagen tissue zinc is essential, other nutrients are also necessary, but zinc is the most important.
It is recommended to consume 12 to 15 mg of zinc per day and increase this level during pregnancy.
Food sources of zinc include: meat, poultry, beans, nuts, and oysters.
Dietary phytates, found in whole grains and flat bread, can significantly decrease zinc absorption. There is also the possibility that raising your calcium level inappropriately could interfere with zinc absorption.
Zinc can be taken as a supplement and should be taken as a salt, as zinc sulfate, combined with vitamin C. Zinc is best absorbed after a protein-rich meal, preferably not breakfast, which may contain foods high in phytates dietary.
Zinc, pregnancy and the first stage of osteoporosis
The Johns Hospital School of Medicine estimates that 85 percent of pregnant women throughout the developed world have a zinc intake that is insufficient for pregnancy. During pregnancy, zinc requirements increase by 50% during the last 15 to 10 weeks. If the mother does not consume enough zinc, then the zinc in her muscles and bones will be given to the fetus, thus beginning the first stage of osteoporosis. (NOTE: The British Medical Association recommends avoiding or using zinc sulfate with caution during pregnancy, as safety has not been established and it crosses the placenta.)
Calcium and osteoporosis
The reason for the emphasis on the calcium content of bones to prevent osteoporosis, and the neglect of zinc as a critical nutrient, is that when x-rays are taken, zinc and collagen are invisible. When osteoporotic bone is x-rayed and compared to normal bone, it appears transparent because normal amounts of calcium cannot be seen. Doctors often recommend higher calcium intake, but then forget to recommend a zinc supplement to help replace collagen. Unfortunately, without the collagen and zinc, the calcium has nowhere to go, which will cause the development of osteoporosis to continue.
Fractures and zinc
There are two stages to bone healing:
Initially, after the fracture, an extensive blood clot forms around the ends of the fractured bone. Collagen-forming cells invade the blood clot and produce a specialized form of collagen that wraps around the fracture. Slowly, the bone-forming cells move into the collagenous tissue, now called the callus. These cells deposit calcium, which gives the bone its strength again.
If the patient receives zinc supplementation immediately after the fracture occurs, a large amount of collagen tissue is rapidly formed, since the enzymes responsible for depositing the bone callus are activated by the zinc. Zinc is not only responsible for rapidly increasing the amount of collagen tissue around the fracture, it is also responsible for activating bone cells that deposit calcium into the collagen tissue.
exercise and zinc
It is paradoxical that the physical exercise that is recommended for the prevention and treatment of osteoporosis can also increase it if the person exercising does not have enough nutrients, particularly zinc. People who exercise excessively lose a significant amount of zinc through sweat. Hourly loss of zinc in sweat can exceed 24-hour urinary zinc excretion by 50%.
In the United States, this condition is called ‘brittle bones, but good body’. In women, the condition is also accompanied by amenorrhea (cessation of menstruation), as zinc deficiency can decrease ovarian activity.
Menopause
In the period leading up to menopause, collagen formation tends to slow as hormone activity declines. Beyond menopause, zinc deficiency may be more pronounced with accelerated loss of collagen and calcium. If collagen loss is due to a lack of zinc, calcium excretion may increase.
One of the effects of reduced estrogen production is increased excretion of hydroxyproline, an amino acid essential for stabilizing collagen structure. Calcium will do nothing to prevent this from happening. Therefore, it is important to guard against the reduction of your collagen tissue in menopause. This is achieved by maintaining an adequate intake of nutrients, including zinc.
Zinc is an important (and often underestimated) nutrient for the prevention of osteoporosis. Zinc is often deficient in the diet, and at times of increased need, such as during pregnancy or menopause or during heavy exercise, zinc levels in the body can be low.
References
Bland, J. 1996, Contemporary Nutrition. J&B Associates.
Davies, S. and A. Stewart., 1997, Nutritional Medicine. Pop.
Fitzherbert, JC 2002, Osteoporosis: The Lost Zinc. Wellness, Number 87.
Holden, S., Hudson, K., Tilman, J. & D. Wolf, 2003, Nature’s Ultimate Guide to Health. Astrology publication.
Pressman, A. and S. Buff, 2000, The Complete Idiot’s Guide to Vitamins and Minerals. (2nd ed.) Alpha Books.
Soothill, R. 1996, The Vitamin and Mineral Choice Guide. A choice book publication.
Sullivan, K. 2002, Vitamins and Minerals: A Practical Approach to a Healthy Diet and Safe Supplementation. HarperCollins.