Intake and food sources of ascorbic acid in China

Investigating differences in the intake of nutrients is of potential importance in characterizing diet-disease relationships and determining the level of intake necessary for optimal health. The intake and food sources of ascorbic acids were examined in an ecologic study of 64 rural counties in the People's Republic of China and compared with data reported for the United States. The mean (± SEM) and median individual intakes of ascorbic acid for all counties combined were 140 (± 88) and 128 mg/day, respectively (range 6-429 mg/day). This compares to a mean intake of 99 mg/day for adult men and 84 mg/day for adult women in the United States. The foods that contributed the most to ascorbic acid intake were sweet potatoes (37.2%), cabbages (23.9%), leafy green vegetables (10.6%), radishes (8.8%), and hot peppers (6.5%). In contrast to the US, where fruits supply 43% of ascorbic acid to the diet, fruits contributed a relatively small amount to overall ascorbic acid intake in rural China ( 1%). The wide range of ascorbic acid intake among counties resulted, in part, from differences in the availability of fresh produce which is grown and consumed locally. Despite this, the mean intake was still greater than the US because of the large contribution of plant products (approximately 90%), especially tubers and other vegetables, to the diet.