Zinc Supplementation May Boost Immunity in Elderly

Zinc supplementation in older patients could help boost their immunity.

Researchers recently studied the effects of daily 30 mg zinc supplementation for 3 months among nursing home residents to determine whether their serum zinc concentrations could improve. Their previous research had shown that around one-third of nursing home residents have low serum zinc levels and that these patients face increased risks for pneumonia and morbidity.

Of the 53 nursing home patients aged 65 years or older, 31 (58%) had low serum zinc concentrations. These Boston-area patients were assigned to either zinc supplementation or placebo.

In addition to analyzing the supplementation’s effects on serum zinc concentrations, the investigators also examined the effects on immune response.

Through their research, they determined that zinc supplementation was effective at improving serum zinc concentrations in the residents, and this increase in serum zinc concentrations was associated with enhancement of T cell function. Those in the treatment group saw an increase of serum zinc levels at a rate of 16%, while levels among the control group rose at a rate of 0.7%.

The study authors said this strongly suggests that by ensuring appropriate zinc intake in elderly patients, the incidence of and morbidity from infection may be significantly impacted.

However, not all the zinc-deficient patients saw adequate concentrations even with supplementation. Those who were substantially deficient in zinc at the start of the trial did not see an increase to a normal level.

“Having a positive response to zinc supplementation may take some time in people who have been highly zinc deficient,” said study author Junaidah B. Barnett, MCH (N), PhD, in a press release. “We need to better understand how much supplementation is needed for certain people, and for how long a period, so that more refined recommendations can be made.”

The researchers said that zinc deficiency is a problem for not only nursing home residents, but also “noninstitutionalized older adults,” said lead study author Simin Nikbin Meydani, DVM, PhD, in a press release.

“On average, zinc supplementation measurably improved serum zinc levels in these older adults, with most participants achieving serum zinc levels considered to be adequate,” Dr. Meydani said.

In addition to supplementation, patients can absorb zinc through foods like oysters, pork, red meat, poultry, seafood, fortified breakfast cereals, beans, nuts, whole grains, cucumber peel, and dairy products.

The study findings were published in The American Journal of Clinical Nutrition.