Maintaining bone strength as we enter mid-life and beyond is an important goal, not just for postmenopausal women. Men may experience declining bone strength as they age, although generally later in life than women. Most people know that adequate calcium intake is important for healthy bones. It is not widely understood, however, that bone is a complex living tissue continually undergoing a process of building up and breaking down. Strong bones require a constant supply of a variety of nutrients, not just calcium.
What Is Osteoporosis?
Osteoporosis is a disorder of the skeleton characterized by decreased bone strength and increased susceptibility to fractures. Osteoporosis is a tremendous world wide medical problem. Hip fractures are the most debilitating consequence of osteoporosis. Wrist and vertebrae fractures also occur. In the U.S. the prevalence of osteoporosis in men and women is estimated to increase from 10 million people in 2002 to 14 million by 2020.1 In the U. S. there are 1.5 million osteoporotic fractures per year, costing $18 billion.2
A Review of Calcium Supplementation
Recommended intake of calcium in people at risk for osteoporosis is 1000 to 1500 mg of elemental calcium per day, in 3 to 4 divided doses. Calcium may be obtained from supplements or food. People greater than 50 years old or with low bone mineral density require ranges at the higher end – 1200mg to 1500 mg daily.
Adequate calcium intake decreases the rate of bone loss in postmenopausal women from 2% per year to 0.25% to 1% per year. Long term calcium supplementation decrease primary fracture rates by 30% to 35%. 3
It is important to note the amount of elemental calcium per tablet or capsule on supplement labels. Calcium is not present by itself; it must be delivered in salt form. Different salts of calcium provide different amounts of elemental calcium per given weight of the salt. The number of tablets or capsules per day you take to get 1000 mg of calcium will vary depending upon the product you choose. Calcium carbonate is 40% calcium. To obtain 500 mg of elemental calcium you need to take 1500 mg of calcium carbonate. Calcium citrate is 21% calcium. Nine hundred and fifty mg of calcium citrate are required to deliver 200 mg of calcium. As an example, to obtain 1000 mg of calcium from calcium carbonate you need to take two tablets of a commonly available product. To obtain 1000 mg of calcium from calcium citrate, a typical product requires 5 tablets per day. Read labels carefully.
Another important consideration in product selection is the degree to which various salt forms are absorbed from the stomach. Calcium carbonate and calcium triphosphate require an acid environment in the stomach to be absorbed. Calcium citrate, lactate and gluconate do not. This difference in absorption characteristics is important for two categories of people – the elderly and those on medications that reduce gastric acidity. The elderly commonly experience age related decrease in stomach acid secretion. Medications that reduce stomach acid, such as those prescribed for ulcers or gastric reflux, raise the pH of the stomach contents. Both situations create an environment unfavorable for absorption of calcium from carbonate and triphosphate salts. For the elderly and those on acid blocking medications, calcium citrate, lactate or gluconate is a better choice.
Calcium carbonate is best taken with meals. Calcium citrate can be taken without regard to meals.
Constipation with calcium supplementation is a problem for some. Changing from calcium carbonate to calcium citrate may help. Taking calcium with magnesium in a 2:1 ratio may also be of benefit. Drinking plenty of water and getting adequate fiber and exercise is also useful.
Vitamin D is required for absorption of calcium. Vitamin D deficiency is wide spread, especially in people living in northern climates. According to a scientific review, “inadequate vitamin D intake may be a greater concern that poor calcium intake, as vitamin D may not be as prevalent in the diet as calcium, and patients may be less aware of vitamin D requirements than calcium.”1 Studies have shown that vitamin D, even without calcium supplementation, reduces fracture rates. Vitamin D also contributes to strong muscles, which reduce the risk of falling.
A meta-analysis is a study that re-analyzes data from many previous studies. A meta-analysis on vitamin D looked at the minimum effective dose.4 Taking only 400 units a day had no effect on fracture rates. Doses of at least 700-800 units daily were required to reduce fracture rates; at this level a 26% reduction was observed. Some doctors suggest that daily doses should be significantly higher, in the range of 1000-2000 units per day. Ask you physician about your optimum dose of vitamin D.
Other Nutrients For Bone
In addition to calcium and vitamin D, the following nutrients may contribute to bone health: vitamin K, magnesium, zinc, copper, manganese, boron, strontium, silicon, and vitamins C, B6, B12, and folic acid.3,5
Vitamin K is required for the production of osteocalcin, a protein found in bone that plays a role in mineralization. People with osteoporosis tend to have suboptimal levels of vitamin K. Two forms of vitamin K occur in food: Vitamin K1 and K2. Vitamin K1 is found in green leafy vegetables. Vitamin K2 is found in meat, eggs and fermented cheese. A particular form of vitamin K2, called menaquinone-7 (MK-7) appears to be most active on bone. MK-7 is found in natto (fermented soy beans).
Magnesium deficiency is associated with abnormal bone formation and implicated in osteoporosis. Preliminary evidence indicates that supplementation may decrease bone loss in postmenopausal women with osteoporosis. A dose of 125 mg to 750 mg daily of magnesium hydroxide was shown to increase bone density over 2 years.6
Zinc decreases bone loss and is found in high amounts in bone and muscle. Zinc deficiency is common, especially in the elderly.
Copper participates in bone modeling by decreasing bone loss and increasing bone mineralization.
Manganese is important for the building up of connective tissue and bone. There is some evidence that deficiency is associated with osteoporosis.
Boron may enhance the effects of estrogen and testosterone on bone. Low boron in the diet is associated with calcium loss
Strontium is a trace element that stimulates bone formation and inhibits bone breakdown. A drug for osteoporosis available in Europe, called Protelos, is a form of strontium. According to Dr. Allen Gaby, MD, low, physiologic doses of strontium are more effective than high pharmacologic doses. (3) Dr. Gaby suggests that pharmacologic doses may contribute to lower quality bone formation.5
Silicon is a trace mineral found in the body, concentrated in connective tissue. Silica is silicon dioxide, a natural source of silicon found in seafood, grains, fruits and vegetables. Beer and bananas are good sources of dietary silica. Dietary intakes of silica in the range of 40 mg per day are associated with higher bone mineral density. Silicon is not to be confused with silicone, a synthetic substance used in breast implants and medical tubing.
Vitamin C is required for synthesis of bone and connective tissue.
Vitamins B6, B12, and folic acid are associated with reduced hip fractures in the elderly. Research on the bone building actions of these vitamins is preliminary and not yet well defined. The benefits on bone are related to a reduction in homocysteine, a breakdown product of protein.
Broad-spectrum vitamin / mineral supplements containing the above bone conserving co-factors are available through manufacturers that market to healthcare professionals. Check with your doctor or pharmacist for dosages. Your physician will guide you on a comprehensive diet, exercise and supplement plan. If you are experiencing bone loss, your physician may suggest a bisphosphonate (Fosamax, Actonel, Reclast, Boniva) or raloxifene (Evista). Drug therapy does not preempt good bone nutrition – both are required.
These statements have not been evaluated by the Food and Drug Administration. They are not intended to diagnose, cure, prevent or treat any disease. Information presented in this article is for educational purposes only and does not constitute medical or professional advice.
1) MacLaughlin, E, et. al. Management of age-related osteoporosis and prevention of associated fractures. Therapeutics and Clinical Risk Managaement 2006: 2(3) 281-295
2) Rosen, C. Postmenopausal Osteoporosis. NEJM 353:6, Aug. 11, 2005
3) Jellen, J, editor. Natural Medicines Comprehensive Database. Stockdale, CA
4) Bischoff-Ferrari, HA et. al. Positive association between 25-hydroxy vitamin D levels and bone mineral density; a population-based study of younger and older adults. Am. J Med. 116:634-9.
5) Bone Health, by Alan Gaby, MD. Integrative Interventions
6) Stendig-Evans, J, et. al. Trabecular bone density in a two year controlled trial of peroal magnesium in osteoporosis. Magnes. Res. 1993;6: 155-163
Debbie Edson is a registered pharmacist, with a background in hospital and community practice. She is proprietor of Healthy Morning, LLC. Her passion is educating people about evidence based natural healing. She is a recent contributor to the best selling book, Prescription For Nutritional Healing, 4th Ed. Debbie lives in Massachusetts with her husband, David. She has one child, Laura Novak, who is a photographer in Wilmington, Delaware.