Ascorbic acid requirements for smokers: analysis of a population survey

Area of Science:

• Nutritional Science
• Public Health
• Clinical Nutrition

Background:

• The Recommended Dietary Allowance (RDA) for ascorbic acid (vitamin C) in smokers was recently raised to 100 mg.
• Smokers exhibit lower serum ascorbic acid (AA) concentrations compared to nonsmokers.
• The adequacy of the new RDA for smokers in preventing low serum AA concentrations remains unclear.

Purpose of the Study:

• To evaluate if the updated RDA of 100 mg ascorbic acid (AA) for smokers is sufficient to normalize serum AA levels and reduce the risk of low concentrations.
• To compare serum AA levels and the risk of low concentrations between smokers and nonsmokers across varying AA intakes.

Main Methods:

• Analysis of dietary AA intake and serum AA concentrations from 11,582 adults in the National Health and Nutrition Examination Survey (1976-1980).
• Comparison of serum AA levels and risk of low concentrations (defined as < 23 µmol/L) in smokers with different AA intakes against nonsmokers meeting the baseline RDA (60 mg).

Main Results:

• Smokers consuming >60 mg, >100 mg, and >150 mg of AA daily showed reduced serum AA concentrations and increased risk of low concentrations.
• Only smokers with an AA intake exceeding 200 mg/day achieved serum AA concentrations and risk of low concentrations comparable to nonsmokers meeting the 60 mg RDA.

Conclusions:

• The current RDA of 100 mg ascorbic acid (AA) for smokers is insufficient to achieve serum AA levels and risk profiles similar to nonsmokers.
• Smokers require significantly higher daily ascorbic acid intake, exceeding 200 mg, to reach optimal vitamin C status comparable to nonsmokers.