Cellular ascorbate depletion in healthy men

Area of Science:

• Human Nutrition
• Biochemistry
• Reproductive Health

Background:

• Ascorbic acid (vitamin C) is essential for numerous physiological functions.
• Understanding the relationship between plasma and cellular ascorbic acid is crucial for accurate nutritional assessment.
• Previous research has not fully elucidated the correlation across various cell types and its implications for monitoring.

Purpose of the Study:

• To investigate the correlation between plasma ascorbic acid and cellular ascorbic acid levels (lymphocytes, buccal cells, semen) in healthy men.
• To determine the reliability of plasma ascorbic acid as an indicator of cellular vitamin C status.
• To assess the impact of varying ascorbic acid intakes on semen and sperm quality.

Main Methods:

• Eight healthy men participated in a 13-week controlled feeding study.
• Participants consumed daily ascorbic acid intakes of 5, 10, 20, 60, or 250 mg.
• Plasma, lymphocyte, buccal cell, and semen ascorbic acid levels were measured, alongside semen and sperm quality parameters.

Main Results:

• All specimen types showed significantly lower ascorbic acid levels at intakes of 5, 10, or 20 mg/d compared to 60 or 250 mg/d.
• Plasma and lymphocyte ascorbic acid levels showed strong correlations and unequivocally discriminated between low and high intakes.
• Buccal cell ascorbic acid showed potential as a noninvasive screening tool; semen and sperm quality remained unaffected by depletion or moderate supplementation.

Conclusions:

• Plasma ascorbic acid levels reliably reflect lymphocyte ascorbic acid status, making plasma a viable indicator for nutrition monitoring.
• Buccal cell ascorbic acid may serve as a practical, noninvasive marker for identifying vitamin C deficiency.
• Short-term vitamin C depletion or moderate supplementation did not adversely affect male fertility parameters.