Patterns of vitamin C intake from food and supplements: survey of an adult population in Alameda County, California.

Use of vitamin C in food and pills and its association with health habits and health status were investigated in a random sample of 3,119 adults in Alameda County, California. Vitamin C intakes of nearly 80 per cent of respondents met or exceeded Recommended Daily Dietary Allowances. Fourteen per cent or fewer appeared to have inadequate vitamin C intake. Vitamin C supplements were taken daily by 29 per cent, occasionally by 21 per cent. Most respondents obtained 100 mg or less of vitamin C daily; 2 per cent had more than 2000 mg. Proportionately, more women than men took vitamin C pills daily. Men aged 16 to 44 were the most likely to have neither vitamin C foods nor pills. Persons 45 years and older tended to take vitamin C pills daily, younger persons to take them occasionally. Respondents who did not eat breakfast or who smoked cigarettes had lower vitamin C intakes. People in poor health took more vitamin C than those in good health. Health status may have influenced vitamin C intake rather than vitamin C intake influencing health status.