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Calcium for bone health

Doctors know that calcium helps protect bone but many have worried that supplementing with calcium might contribute to hardening of the arteries, also known as coronary artery calcification, a factor in heart disease. In this study from Harvard Medical School, researchers measured the diets of 1,278 men and women aged 36 to 83, and then took a CAT-scan x-ray four years later.

Those who got the most calcium from diet, from supplements, or from both, had the same coronary artery calcification scores as those who got the least calcium. Doctors said, “This study addresses a critical question about the association between calcium intake and a clinically measurable indicator of atherosclerosis in older adults. There was no increased risk of calcified arteries with higher amounts of calcium intake from food or supplements, and people who take calcium at the recommended levels for bone health can do so safely without worrying about calcifying their arteries.”

Reference: American Journal of Clinical Nutrition; 2012, Vol. 96, No. 6, 1274-80

From the March 2013 Newsletter

CLA helps manage weight

CLA, or conjugated linoleic acid, had several benefits including reducing body fat in earlier animal studies, but human studies have been inconclusive, doctors said. In this study, 63 people tending toward overweight or obesity took 1,700 mg of CLA per day, or a vegetable oil placebo, in about 7 ounces of sterilized milk. After 12 weeks, while there were no changes for placebo, the CLA group had lost body weight, improved body mass index score, had less total fat and fat under the skin, a lower percentage of body fat, and a smaller waist-to-hip size. The higher the body mass index at the start of the study, the larger the improvements in all measures.

Calcium burns fat, reduces fat absorption

When dieters take in fewer calories than they burn, calcium supplements may stimulate fat loss, but prior studies have been inconclusive, doctors said. In this review, researchers analyzed eight placebo-controlled calcium weight-loss studies, and found that dieters who got high levels of calcium increased fat metabolism by 11 percent compared to placebo. Those who consumed low levels of calcium before the study-less than 700 mg per day-saw the most fat-loss benefit. Researchers said the higher rate of fat-burning was equal to losing eight pounds per year.

In discussing their findings, doctors said that calcium supplements raised the metabolic rate as effectively as caffeine. The average amount of calcium linked with the largest weight-loss benefit was 958 mg of calcium per day. Doctors also said good calcium levels help control appetite.

Reference: American Journal of Clinical Nutrition; October, 2012, Electronic Prepublication

From the January 2013 newsletter

Calcium, vitamins D and K in celiac disease.

Children with celiac disease may have weak bones because they don’t absorb fat-soluble vitamins such as vitamin D. In this study, 43 children aged 3 to 17, with celiac disease, agreed to follow a gluten free diet. At the start, 43 percent were low in vitamin D and 25 percent were low in vitamin K, with a direct link to lower bone mineral density (BMD) scores.

After one year, BMD scores had not changed. One-third of the children were still not getting enough vitamin K on the gluten free diet, and all the children were getting too little calcium and vitamin D. Study authors said children with celiac disease should supplement at least the recommended daily allowance of calcium, vitamin D, and vitamin K.

Overweight kids deficient in vitamin D

Doctors in this study compared vitamin D levels in 411 obese kids, aged 6 to 16, to 87 normal-weight kids of the same age. Children told researchers about their daily diets including soda, juice, fruit and vegetables, as well as how often they skipped breakfast. Half of the obese children were deficient in vitamin D, compared to 22 percent of normal-weight kids, and 92 percent were low in vitamin D, compared to 68 percent for normal-weight kids. The more kids skipped breakfast, drank soda, and fruit juice, the lower the levels of vitamin D.

Obese kids were also more likely to show signs of insulin resistance, and doctors said that while this study does not prove a cause-and-effect relationship, they suspect low vitamin D levels may play a role in developing type 2 diabetes.

Reference: The Journal of Clinical Endocrinology and Metabolism; 2012, Vol. 97, No. 1, 279-85

From the April 2012 newsletter

Omega-3s plus exercise

The lower estrogen levels in postmenopause cause bone loss, and inflammation, if present, increases chances of fracture. Anti-inflammatory omega-3 fatty acids help strengthen bone by suppressing the activity of osteoclasts, cells that remove healthy minerals from bone. In this study, 79 healthy postmenopausal women split into four groups. One group did not exercise or take supplements. A second walked and jogged only, up to 65 percent of maximum heart rate. A third group took 180 mg of eicosapentaenoic acid plus 120 mg of docosahexaenoic acid (EPA/DHA) per day, while a fourth group took the omega-3s and exercised.

After 24 weeks, while there were no changes in the other groups, the exercise/omega-3 group had 40 to 80 percent lower signs of inflammation, 15 percent greater bone mineral density (BMD) in the lower back, and 19 percent more in the thigh bone and hip.

Copper, magnesium, zinc

In this BMD study, 224 postmenopausal women, aged 51 to 80, took a multivitamin providing adequate vitamin D, plus 600 mg of calcium alone, or 600 mg of calcium with 12 mg zinc and 2 mg copper. The women kept a food diary to measure total nutrients from food and supplements.

After two years, women who got less than the recommended dietary allowance (RDA) for copper, magnesium, or zinc had poorer bone health than women who got at least the minimum RDA. The RDA for copper is 0.9 mg, for magnesium 237 mg, and zinc 8 mg per day. For zinc, women who got between the minimum RDA of 8 mg per day and up to 20 mg per day; 2.5 times the RDA, had healthier bones than the women who got more or less zinc.

Reference: British Journal of Nutrition; December, 2011, Vol. 106, No. 12, 1872-9

From the March 2012 newsletter

Vitamins B1 and B2 reduce PMS

Researchers in this study collected diet information for five years from 3,025 women who began the study without PMS. After a total of 10 years of follow-up, 1,057 women developed PMS. Compared to women who consumed the least, women who got the most vitamin B1 (thiamine) were 25 percent less likely to develop PMS, and for vitamin B2 (riboflavin), were 35 percent less likely.

Calcium and vitamin D may reduce chances of serious skin cancer

There are two classes of skin cancer; non-melanomas such as basal and squamous cell, and more-serious melanomas. Earlier research linked higher levels of vitamin D with lower chances of non-melanomas, and doctors in this study wanted to test vitamin D against melanoma. Researchers gave 36,282 postmenopausal women, aged 50 to 79, 1,000 mg of elemental calcium plus 400 IU of vitamin D per day, or a placebo. After seven years of follow-up, while there were no differences between groups overall, in a subgroup of women who had had a previous non-melanoma skin cancer, those in the calcium-vitamin D group had 57 percent fewer melanomas than the placebo group.

Discussing the results, study authors said, “In preventive medicine, we want to target people most at risk for the disease. If you previously had a non-melanoma skin cancer, calcium plus vitamin D might reduce your risk for more deadly melanoma.”

Reference: American Journal of Clinical Nutrition; 2011, Vol. 93, No. 5, 1080-6

From the October 2011 newsletter

During puberty, girls usually develop more than a third of their adult peak bone mass, setting the stage for healthier bones later in life and lowering chances of osteoporosis. In this study of twenty pairs of identical twin girls, approaching or in puberty and aged 9 to 13, one sister took 800 mg of calcium plus 400 IU of vitamin D3 per day while her twin took a placebo. After six months, doctors measured bone strength and found, compared to placebo, girls in the calcium-vitamin D group had up to 66 percent stronger shin and arm bones depending on the specific area of the bone. Researchers said that bone size, density and strength increased in the spongy-bone areas inside of bones and in the compact-bone areas along the outer shafts of the arm and shin.

Reference: Osteoporosis International; 2011, Vol. 22, No.2, 489-98

From the July 2011 newsletter