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Therapeutics

Vitamin and trace-element supplementation in healthy elderly persons reduced the frequency of infection and nutritional deficiencies and improved immune response

ACP J Club. 1993 Mar-April;118:34. doi:10.7326/ACPJC-1993-118-2-034


Source Citation

Chandra RK. Effect of vitamin and trace-element supplementation on immune responses and infection in elderly subjects. Lancet. 1992 Nov 7;340:1124-7.


Abstract

Objective

To study the incidence of infections and nutritional status and immune markers in healthy elderly persons who were given vitamin and trace-element supplements in physiologic doses.

Design

1-year randomized, double-blind, placebo-controlled trial.

Setting

Community study in Newfoundland.

Participants

96 healthy volunteers > 65 years (55 women) living independently. All were middle class and of English or Irish descent, with no chronic illnesses, and were not taking medications that could interfere with nutritional status or immunocompetence. 90% completed the study.

Intervention

48 people were randomly assigned to take an oral vitamin and trace-element nutritional supplement based on current Canadian and U.S. recommendations, except for vitamin E and β-carotene, which were at 4 times the recommended dose. The supplement contained vitamin A, 400 retinol equivalents; β-carotene, 16 mg; thiamine, 2.2 mg; riboflavin, 1.5 mg; niacin, 16 mg; vitamin B6, 3.0 mg; folate, 400 µg; vitamin B12, 4.0 µg; vitamin C, 80 mg; vitamin D, 4 µg; vitamin E, 44 mg; iron, 16 mg; zinc, 14 mg; copper, 1.4 mg; selenium, 20 µg; iodine, 0.2 mg; calcium, 200 mg; and magnesium, 100 mg. 48 people were assigned to placebo (calcium, 200 mg, and magnesium, 100 mg).

Main outcome measures

Participants were interviewed every 2 weeks and reported any illnesses and infections. Infections were confirmed by blood counts, laboratory tests, radiographs, cultures, and sedimentation rates. Nutritional status and immunologic data were collected before and after the study.

Main results

At study end, participants in the supplement group had fewer infection-related illness days (23 vs 48 d {95% CI for the 25-d difference 23 to 28 d}*; P = 0.002); fewer days taking antibiotics (18 vs 32 d, {CI for 14-d difference 12 to 16 d}*, P = 0.004); and fewer nutritional deficiencies (vitamin A, β-carotene, vitamin B6, vitamin C, iron, and zinc [ P ≤ 0.05 for all comparisons]). The supplement group also had markers of greater immune responses (more T cells, natural killer cells and activity, lymphocyte response to phytohemagglutinin, and interleukin-2 production and receptor release [ P ≤ 0.02 for all comparisons]).

Conclusion

Physiologic intake of essential vitamins and trace elements reduced the frequency of infections and nutritional deficiencies and improved immune response in healthy, independently living elderly persons.

Sources of funding: Nutrition Research Education Foundation and Memorial University of Newfoundland.

For article reprint: Dr. R.K. Chandra, Janeway Child Health Centre, St. John's, Newfoundland A1A 1R8, Canada. FAX 709-778-4191.

*Numbers calculated from data in article.


Commentary

The elderly population is growing rapidly, and it is estimated that by the year 2040 more than 20% of the American population will be over 65 years of age. Infection remains the fourth most common cause of death and represents a frequent cause of illness in elderly persons. Protein energy malnutrition and the isolated deficiency of certain micronutrients have been associated with an impaired immune response. Excessive micronutrient supplementation, however, may actually impair cellular immune function. Elderly persons are especially susceptible to malnutrition caused by poor diets, chronic illnesses, and multiple medications.

This study evaluated the effect of multivitamin and trace mineral supplementation on clinical outcome. It is important to note that the supplement given was similar to the current recommended daily allowances except for β-carotene and vitamin E, which were approximately 4 times the recommended allowances. The supplemented group showed increased immunologic responses, correction of vitamin deficiencies, and fewer days of infection-associated illness and antibiotic use. Illness severity and need for hospitalization, however, were not specifically evaluated. It was not noted whether participants who had nutritional deficiencies had increased rates of infection compared with nutritionally replete persons.

The results and issues raised by this study are clearly important ones. Major questions, however, remain unanswered. Were the positive results caused by the correction of nutritional deficiencies? Were the positive results caused by single nutrients given in excess amounts (β-carotene or vitamin E)? In a randomized, double-blind, controlled trial in community-living, elderly people, Meydani and colleagues showed that vitamin E, 200 mg, enhanced cell mediated immunity (1). Other studies have supported these findings (2, 3). Clinical outcomes of incidence and morbidity of infections remain to be established, particularly in the frail elderly (4). For now, it would be prudent for physicians to consider supplementation of elderly persons who have poor diets or appetites, who are house-bound, or who are in a nursing home. Until these questions are answered, however, it is premature to recommend the routine multivitamin and mineral supplementation of elderly persons.

John R. Saltzman, MD
University of Massachusetts Medical CenterWorcester, Massachusetts, USA


References

1. Meydani SN, Meydani M, Blumberg JB, et al. Vitamin E supplementation and in vivo immune response in health elderly subjects. A randomized controlled trial. JAMA. 1997;277:1380-6.

2. Bogden JD, Oleske JM, Lavenhar MA, et al. Effects of one year of supplementation with zinc and other micronutirents on cellular immunity in the elderly. J Am Coll Nutr. 1990;9:214-5.

3. Chavance M, Herbeth B, Mikstacki T, et al. Nutritional support improves antibody response to infuenza virus vaccine in the elderly. Br Med J (Clin Res Ed). 1985;291:1348-9.

4. Chandra RK. Graying of the immune system. Can nutrient supplements improve immunity in the elderly? JAMA 1997;277:1398-9.