Are the Recommended Dietary Allowances for Vitamins Appropriate for Elderly People?

Abstract

Background: An adequate vitamin intake is essential for a good nutritional status, especially in older women, who are more sensitive to nutritional deficiencies. The American, European and Italian Recommended Dietary Allowances (RDAs) derive mainly from studies on adults, and it is not clear whether they also apply to elderly people. Comparing the RDAs with the actual vitamin intake of a group of healthy older women could help to clarify the real needs of elderly people.

Objective: Our aim was to compare the American, European, and Italian RDAs with the actual vitamin intake of a group of healthy older women.

Design: This was a cross-sectional study.

Participants: The study included 286 healthy women aged older than 65 years.

Main outcome measures: For each micronutrient, the 50th percentile of the distribution of its intake was considered as the average requirement, and the corresponding calculated RDA for our sample was the average requirement×1.2, as recommended by the US Food and Nutrition Board. This calculated RDA was then compared with the American, European, and Italian RDAs.

Statistical analyses performed: Student's t test or the Mann-Whitney test (after checking the normal distribution of the micronutrient) for continuous variables; the χ(2) test for categorical variables.

Results: The calculated RDA were 2,230 μg retinol equivalents for vitamin A, 2.8 μg for vitamin B-12, 0.9 mg for thiamin, 1.4 mg for riboflavin, 3.6 mg for pantothenic acid, 1.4 mg for vitamin B-6, 320 μg for folic acid, and 115 mg for vitamin C.

Conclusions: Our findings suggest that the current RDAs are adequate for older women's intake of riboflavin, vitamin B-6, and folic acid, but should be raised for vitamin B-12 and for vitamin C.

Keywords: Micronutrient; Older people; Recommended Dietary Allowances (RDA); Vitamins.