Extra Calcium Safe for the Aging Eye

FRIDAY, March 22, 2019 (HealthDay News) -- To take calcium or not to take calcium, that is still the question.

In a new study that contradicts earlier research, investigators found that adding calcium to your diet will not raise your risk of a common age-related eye disease.

That disease, age-related macular degeneration (AMD), is a leading cause of vision loss and blindness among Americans aged 65 and older.

In the new research, a team from the U.S. National Eye Institute analyzed data from more than 4,700 people in the United States who were followed for an average of 10 years as part of a study on age-related eye disease. None of the participants had AMD at the start of the study.

As participants got older, those with the highest intake of calcium from their diet or supplements actually had a lower risk of developing late-stage AMD than those with the lowest calcium intake, the findings showed.

The study was published March 21 in JAMA Ophthalmology.

"Although the findings suggest that high calcium intake may be protective, the jury is still out on whether people should alter their calcium intake to prevent the onset or progression of AMD," said lead investigator Dr. Emily Chew.

She is director of the division of epidemiology and clinical applications, and deputy clinical director at the eye institute.

Chew noted that the apparent protective effect of calcium could be due to other factors. For example, people who have a high calcium intake may be more likely to also eat a healthier diet, exercise and take prescribed medications, all of which could also lower AMD risk.

About 50 percent of men and 65 percent of women in the United States regularly use calcium supplements for strong bones and teeth, and to prevent and treat osteoporosis. Recommended daily amounts of calcium are 1,000 milligrams (mg) for adults 50 and younger, and 1,200 mg for those over 50.

"These latest findings provide no evidence that there is a need to change the management of calcium intake for individuals who are already taking calcium for other medical indications," Chew said in an eye institute news release.

Further research is needed to determine if calcium does actually protect against AMD, Chew concluded.

More information

The U.S. National Eye Institute has more on AMD.