Supplement Doses can be too High for some Older Women
Older women should be careful about consuming calcium and vitamin D sourced from supplements, a new study reported. According to the researchers, even though older women are often recommended to add supplements to their diets, for some women, normal doses can lead to elevated levels that are considered harmful.
"Even a modest calcium supplementation of 500 mg/day may be too high for some women," the authors concluded according to the press release.
In this study, the researcher recruited 163 white women between the ages of 57 and 90. All of the women had low vitamin D levels. The participants took calcium citrate tablets and different dosages of vitamin D, ranging from 400 to 4,800 international units (IU) per day. The researchers pointed out that since different ethnic groups metabolize calcium and vitamin D differently, they had to limit their study to only one ethnic group.
The researchers measured the participants' calcium levels. Even though the women did not intake more than the recommended value of calcium per day, nine percent of them had hypercalcemia, which occurs when calcium levels in the blood are elevated. 31 percent of the women ended up having high calcium levels in their urine, known as hypercalciuria. Elevated levels of calcium in the blood or urine can lead to health complications, such as kidney stones.
Despite finding side effects of taking normal doses of calcium, the researchers were able to identify certain risk factors. They reported that women who had a 24-hour urine calcium level that was higher than 132 mg were 15 times more likely to develop hypercalciuria. When the starting levels were higher than 180 mg, the risk increased by 20 times. The researchers also found that as women aged, their risk of developing hypercalciuria fell by 10 percent per year.
"I would recommend that women determine how much calcium they typically get through their food sources before taking a hefty calcium supplement. They may not need as much as they think," commented the North American Menopause Society (NAMS) Executive Director Margery Gass, MD.
The study, "Incidence of hypercalciuria and hypercalcemia during vitamin D and calcium supplementation in older women," was published in the North American Menopause Society's journal, Menopause.