Ascorbic acid intake and plasma levels in healthy elderly people

Area of Science:

• Nutritional Science
• Gerontology
• Biochemistry

Background:

• Vitamin C (ascorbic acid) is essential for human health.
• Age-related changes can affect nutrient metabolism and requirements.
• Sex-based differences in nutrient status are observed in various populations.

Purpose of the Study:

• To investigate sex-specific differences in plasma ascorbic acid concentrations in elderly individuals.
• To determine the relationship between vitamin C intake and plasma ascorbic acid levels in older men and women.
• To establish optimal vitamin C intake levels for achieving adequate plasma concentrations in the elderly.

Main Methods:

• Controlled dietary intake of vitamin C in elderly men and women (ages 65+).
• Measurement of plasma ascorbic acid concentrations across a range of vitamin C intakes (30-280 mg/day).
• Statistical analysis to compare plasma levels between sexes and correlate with intake.

Main Results:

• Elderly men exhibited significantly lower plasma ascorbic acid levels than women across all tested vitamin C intakes.
• Maximum steady-state plasma ascorbic acid levels (approx. 1.0 mg/dL) were achieved by men at ~150 mg/day and women at ~80 mg/day.
• At 60 mg/day vitamin C intake, men's plasma ascorbate levels were estimated at 0.4 mg/dL or less.

Conclusions:

• Elderly men require higher vitamin C intake than women to achieve similar plasma ascorbic acid concentrations.
• Sex-based differences in vitamin C metabolism or utilization may persist into older age.
• Dietary recommendations for vitamin C in the elderly should consider sex-specific requirements.