Effect of ascorbic acid on calcium elimination in humans

Area of Science:

• Biochemistry
• Human Physiology
• Nutritional Science

Background:

• Ascorbic acid (vitamin C) is essential for numerous bodily functions.
• Understanding its metabolic effects, particularly on mineral excretion, is crucial for public health.
• Previous research on vitamin C and calcium metabolism has yielded mixed results.

Purpose of the Study:

• To investigate the short-term and long-term effects of high oral doses of ascorbic acid on urinary calcium excretion in healthy humans.
• To determine if ascorbic acid influences calcium absorption and metabolism.

Main Methods:

• Experiment 1: 22 healthy subjects received 10g of ascorbic acid daily; urinary calcium levels were measured before and during treatment.
• Experiment 2: 46 healthy subjects ingested 2g of ascorbic acid; urinary samples were collected over 8 hours to measure calcium, volume, and phosphorus.
• Statistical analysis was performed to compare urinary calcium levels before and after ascorbic acid administration.

Main Results:

• Long-term (10g/day) ascorbic acid intake resulted in no significant urinary calcium changes in 19 out of 22 subjects.
• Short-term (2g) ascorbic acid intake significantly increased mean urinary calcium excretion over an 8-hour period (48.2 mg to 58.3 mg).
• Initially low calcium excretors showed a significant increase in urinary calcium after ascorbic acid, while high excretors did not.

Conclusions:

• Ascorbic acid, particularly in short-term high doses, appears to influence calcium regulation.
• The effect seems more pronounced in individuals with lower baseline urinary calcium levels.
• Further research is needed to fully elucidate the mechanisms of ascorbic acid's impact on calcium metabolism.