Geographical, Seasonal and Gender Differences in Folate Status among Chinese Adults

Abstract

Low blood folate concentrations have been associated with cardiovascular disease, neural tube defects and selected cancers, but little is known about folate status in Chinese adults. In a cross-sectional study we measured the plasma and red blood cell folate concentrations in 2422 Chinese men and women aged 35 to 64 y, living in the North and South of China, who provided blood samples either in March or September of 2001. The geometric mean concentrations of plasma and red blood cell folate were lower among Northerners than Southerners (adjusted geometric means, 8.4 and 502, and 16.7 and 811 nmol/L, respectively) controlling for age, gender, season (spring and fall), area (urban and rural), BMI, multivitamin use, alcohol intake and current smoking status. We estimated that approximately 40% of the Northerners and approximately 6% of the Southerners had plasma folate concentrations lower than the 6.8 nmol/L (3 microg/L), and approximately 30% of the Northerners and approximately 4% of the Southerners had red blood cell folate concentrations lower than the 363 nmol/L (160 microg/L), levels used to define folate deficiency. Within each region, men had lower plasma folate concentrations than women (6.9 versus 9.8 nmol/L in the North, and 14.5 versus 19.6 nmol/L in the South). In men, current smokers had a higher risk of folate deficiency compared with nonsmokers [adjusted odds ratios, 1.9 (95% CI, 1.4-2.6) for plasma folate deficiency and 2.5 (95% CI, 1.7-3.6) for red blood cell folate deficiency (P < 0.001)]. Our findings suggest that a large proportion of Chinese adults have a low folate status, especially those living in northern China where 60% of the men are plasma folate deficient in the spring. Further studies are needed to elucidate the factors that influence folate concentrations among middle-aged Chinese and to evaluate possible intervention strategies.

Folate and vitamin B12status of women of reproductive age living in Hanoi City and Hai Duong Province of Vietnam

“…Nevertheless, the close agreement between the actual and predicted decline in NTD rates in countries with mandatory folic acid fortification suggests the equation is valid (29) for predicting change in NTD rate with a change in population folate status. Furthermore, the finding of lower blood folate concentrations and higher NTD rates in northern v. southern China suggests that this relationship applies in an Asian setting (8) .…”

Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and the risk of primary Hepatocellular Carcinoma (HCC) in a Chinese population

“…Some studies have reported that folate deficiency is fairly common in many Chinese areas, especially northern China including Beijing [40][41][42][43]. In Taixing city, the present study field area, located in the Northern Jiangsu province, the boundary between North and South China, most residents are country people with low consumption of fresh vegetables and fruits due to the relative low economic level.…”

Market Potential of Folate Biofortified Rice in China

“…Until today, there is no evidence of studies that have calculated the health impact of folate deficiency at population level (see section 2.2). Given that Northern China (Hao et al, 2003; see also Figure 7), and Shanxi Province in particular , has one of the highest folate deficiency rates in the world, there is a need to estimate the current burden of this micronutritional disease at regional/provincial level.…”

“…However, evidence on the total number of folate deficient people in China is scarce (WHO, 2009a;Micronutrient Initiative, 2011b). Only two studies reported the folate deficiency rate in Chinese regions, spread across the country (Hao et al, 2003;Zhao et al, 2009). Other folate status and intake assessment studies in China focused on specific regions, characterized by a low NTD prevalence rate, such as in Shanghai (Shrubsole et al, 2001), Jiangsu (Li et al, 1996;Ren et al, 2007) and Anqing (Ronnenberg et al, 2000), or a high prevalence of NTDs, for instance in Shanxi (Li et al, 1996;Zhang et al, 2006;Ren et al, 2007;Zhang et al, 2008) and Beijng (Gao et al, 2003).…”

“…a study on folate deficiency of men and women (Hao et al, 2003) versus the regional folate status of women of childbearing age (Zhao et al, 2009), are summarized in The higher number of folate deficient people in Northern China is partly attributable to the lower availability and the limited variety of fresh vegetables, and the lower consumption of folate-rich food products (Hao et al, 2003). The dietary folate intake of people from Northern China mainly depends on their consumption of grains, while folate-rich food products, such as (green) vegetables, are the main folate sources in Southern China (Zhao et al, 2009).…”