Response of lingual ascorbic acid test and salivary ascorbate levels to changes in ascorbic acid intake

Area of Science:

• Biochemistry
• Nutritional Science
• Clinical Medicine

Background:

• Ascorbic acid (vitamin C) is essential for numerous physiological functions.
• Accurate assessment of vitamin C status is crucial for maintaining health.
• Existing methods for assessing vitamin C status require validation under controlled conditions.

Purpose of the Study:

• To evaluate the reliability of the lingual ascorbic acid test (LAAT) and salivary ascorbate measurements.
• To determine if these oral indicators correlate with plasma and leukocyte ascorbate levels.
• To assess the impact of controlled ascorbic acid depletion and supplementation on these markers.

Main Methods:

• Eleven healthy men underwent a controlled diet regimen with varying daily ascorbic acid (AA) intake (0 mg, 60 mg, 600 mg).
• Oral examinations, LAAT, and measurements of salivary, plasma, and leukocyte ascorbate concentrations were performed throughout the study.
• Participants maintained excellent oral hygiene, with no significant mucosal or periodontal issues observed.

Main Results:

• Plasma and leukocyte ascorbate concentrations showed rapid responses to changes in vitamin C intake.
• Lingual ascorbic acid test (LAAT) values did not correlate with ascorbic acid intake or blood ascorbate levels.
• Salivary ascorbate levels remained consistently low and near the detection limits of the assay.

Conclusions:

• The lingual ascorbic acid test (LAAT) is not a reliable indicator of ascorbic acid status.
• Salivary ascorbate levels do not accurately reflect plasma or leukocyte ascorbate concentrations.
• Current oral-based assessments for vitamin C status lack correlation with established biochemical markers.