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Disclaimer: The following content is provided by Aisle7 and is for informational purposes only. It is based on scientific studies, clinical experience, or usage as cited in each article. Hi-Health provides this information as a service but does not endorse it. In addition, Aisle7 does not recommend or endorse any specific products.
Higher body weight reduces the risk of osteoporosis and related fractures, primarily because more weight on bones causes them to increase their density to support that weight.5,6 Moreover, researchers have shown that people who successfully lose weight have greater loss of bone compared with those who do not lose weight.7 Therefore, people who lose weight need to be more vigilant about preventing osteoporosis.
Due to health consequences associated with being overweight, healthcare professionals do not recommend weight gain for most people in order to reduce the risk of osteoporosis. However, very underweight people, such as those with anorexia nervosa, not only produce less weight-bearing pressure, but also produce less bone-protecting hormones, and may have many nutritional deficiencies that contribute to an increased risk of bone loss.8,9 Weight gain in underweight people may reduce the risk of osteoporosis.
In a group of 980 postmenopausal women, lifetime caffeine intake equal to two cups of coffee per day associated with decreased bone density in those who did not drink at least one glass of milk daily during most of their life.13 However, in 138 postmenopausal women, long-term dietary caffeine (coffee) intake was not associated with bone density.14 Until more is known, postmenopausal women should limit caffeine consumption and consume a total of approximately 1,500 mg of calcium per day (from a combination of diet and supplements).
Good calcium nutrition throughout life is essential for achieving peak bone mass and preventing deficiency-related bone loss.15 Many trials have investigated the effects of calcium supplements on bone mass. Although insufficient when used as the only intervention, calcium supplements have helped to prevent osteoporosis.16 Though some of the research remains controversial, the protective effect of calcium on bone mass is one of very few health claims permitted by the U.S. Food and Drug Administration.
In several studies, calcium intake has not correlated with protection—for example in men17 or in women who have just started menopause.18 Moreover, even most positive studies focusing on the effects of isolated calcium supplementation on bone mass show only minor effects. Nonetheless, a review of the research shows that calcium supplementation plus hormone replacement therapy is much more effective than hormone replacement therapy without calcium.19 Double-blind research has found that increasing calcium intakes results in greater bone mass in girls.20 An analysis of many studies investigating the effects of calcium supplementation in premenopausal women has also shown a significant positive effect.21 Studies in elderly people also confirm the value of calcium supplementation to prevent bone loss and fractures in older individuals.22,23 Most doctors, recommend calcium supplementation as a way to partially reduce the risk of osteoporosis. In order to achieve the 1,500 mg per day calcium intake deemed optimal by many researchers, 800–1,000 mg of supplemental calcium are generally added to diets that commonly contain between 500–700 mg calcium.
Taking thyroid hormones has been reported to increase urinary loss of calcium,51 although recent research suggests that under most circumstances bone density may not be reduced.52,53,54 However, when doses of thyroid medication are higher than necessary and result in suppression of thyroid-stimulating hormone (TSH), adverse effects on bone appear to be more common.55,56 People taking thyroid hormone should have TSH levels measured regularly by their doctor. If TSH levels are low, thyroid hormone dose should be reduced to protect against osteoporosis. Some doctors also suggest that people who supplement thyroid medication for more than a few months consider having 24-hour urinary calcium levels measured. Whether calcium supplementation for people taking long-term thyroid medication is helpful or necessary remains unclear.
Bone formation requires protein, but people concerned with preservation of bone mass can eat too little protein as well as too much. In one trial of older women (average age 82) who had suffered an osteoporotic fracture, those given a 20 gram per day protein supplement had fewer complications, were less likely to die, and had much shorter hospital stays compared with women not assigned to receive extra protein.63 Similarly, in a three-year study of American women aged 50 to 69 funded by the National Dairy Council, those eating more animal protein had a lower risk of osteoporotic hip fracture compared with those eating less.64 A related double-blind trial in older women who had recently suffered an osteoporotic hip fracture found that a 20 gram per day protein supplement reduced bone loss compared with those not receiving protein.65
Pending further research, these conflicting reports show that drawing the line between too much protein and too little remains elusive. Nonetheless, most studies currently suggest that a life-long intake of high animal protein correlates with an increased risk of developing osteoporosis. Protein supplementation following an osteoporotic fracture in elderly people has improved bone health, but less is known about the effects of protein supplementation in the prevention of osteoporosis. People who wish to protect themselves against osteoporosis and who are concerned about protein intake should have a qualified healthcare practitioner analyze their dietary protein intake. (Most Americans eat levels of protein far above recommended levels.)
Soy foods such as tofu, soy milk, roasted soybeans, and soy extract powders may be beneficial in preventing osteoporosis. Isoflavones from soy protect animals from bone loss.80 In women, taking 40 grams of soy protein powder containing 90 mg isoflavones increased bone mineral density of the spine in a double-blind trial.81 However, lower intakes (providing 56 mg isoflavones) did not improve bone density in this report. A synthetic isoflavone, ipriflavone, has reduced osteoporotic bone fractures in several reports.82 Although the use of soy in the prevention of osteoporosis looks hopeful, knowing to what extent soy reduces bone loss will require further research.
One study found that increasing intake of vitamin A in the diet was associated with bone loss and risk for hip fracture, possibly due to a vitamin A-induced stimulation of cells that break down bone.83 Vitamin A is found in high amounts in liver, cod liver oil, fortified dairy products and breakfast cereals, some fish, and vitamin A supplements. Beta-carotene (which can be used by the body to make vitamin A) has not been linked to reduced bone mass. Until more is known, people concerned about osteoporosis and wishing to supplement with vitamin A may consider taking beta-carotene supplements instead.
Vitamin D increases calcium absorption, and older people with hip fractures are often low in vitamin D.84,85 Vitamin D supplements or injections have reduced bone loss or fractures in some,86,87,88 but not all,89,90,91 studies. Commonly, trials reporting reduced risk of fracture have used the combination of vitamin D and calcium compared with placebo, making it impossible to assess the specific benefit of vitamin D.92 Nonetheless, vitamin D does appear partially protective, at least in certain circumstances. Double-blind research indicates that vitamin D supplementation reduces bone loss in women who consume insufficient amounts of vitamin D from food.93 A double-blind trial also supports the use of higher (700 IU per day) supplemental intakes of vitamin D, particularly as a way to reduce bone loss in women during winter and spring, when vitamin D levels are typically at their lowest.94
While people who get outdoors regularly and live in sunny climates are unlikely to need vitamin D supplementation (particularly during the summer), healthcare practitioners often recommend vitamin D to most other people as a way to help protect bone mass despite remaining inconsistencies in the research. Typical supplemental amounts are between 400 and 800 IU per day, depending on dietary intake and exposure to sunlight.
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