Association between dietary folate-rich food intake and folate status of elderly Taiwanese.

To investigate the relationship between folate status and dietary folate intake in the Taiwanese elderly, we analyzed plasma folate levels and dietary folate intake in 725 males and 705 females aged 65-90 years, sampled from the Elderly Nutrition and Health Survey in Taiwan (1999-2000) (Elderly NAHSIT). Results showed that the mean plasma folate levels were 22.9+/-1.4 nmol/L (10.1+/-0.6 ng/ml) for males and 29.5+/-1.6 nmol/L (13.0+/-0.7 ng/ml) for females. The average plasma folate concentrations of males from all age groups were significantly lower than those of females (P<0.0001). None of the study subjects had a plasma folate below 7 nmol/L (3 ng/ml). However, 18.6% of males and 12.1% of females had marginal folate deficiency, with plasma folate between 7-14 nmol/L (3-6 ng/ml). This suggests that elderly males have a poorer folate status than elderly females in the Taiwanese population. The percentage of marginal folate deficiency tended to increase with age among females (P trend=0.0137). The average estimated folate intakes were 379+/-18 microg/d in males and 351+/-27 microg/d in females. However, 45.5% of males and 48.8% of females had a dietary folate intake below 2/3 of the RDA of 400 microg/d. Our results indicated that dietary folate intake is positively correlated with plasma folate levels (r=0.10, P<0.05). In addition, dietary folate intake increased with increased intakes of vegetables, mushrooms and fruit. A lower intake of fruit appeared to be responsible for the higher prevalence of marginal folate deficiency among females over the age of 80 years.