Objective: To analyze the folate status among women of childbearing age worldwide from 2000 to 2020, and explore the impact of socioeconomic factors on folate status, so as to provide support for the formulation of relevant supplementary policies in China in the future. Methods: The "folate" "folic acid" "deficiency" "status" "women" "childbearing" and "reproductive" were used as Chinese and English keywords to systematically search CNKI and PubMed database. Global Health Data Exchange database (GDHx), Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia datasets (BRINDA) and Ground Work publications were systematically searched with "micronutrients" and "nutrition" as keywords. The retrieval time was from January 1, 2000 to August 31, 2020, and the language was restricted to English and Chinese. After title, abstract and full-text screening, a total of 45 literatures were included. The folate status of women of childbearing age in the eligible literature was analyzed, and the income and folate status were tested by Kruskal Wallis H test and Nemenyi test. Results: The M (Q₁, Q₃) of serum folate deficiency rate and erythrocyte folate insufficiency rate in women of childbearing age were 15.0% (3.5%, 37.0%) and 49.0% (22.0%, 83.0%). There were great differences in serum folate status and serum folate deficiency rate among women of childbearing age in different income countries. The serum folate deficiency rate of women of childbearing age in low-income countries was significantly higher than that in middle and high-income countries. Conclusion: The folate status of women of childbearing age in most countries has not reached the ideal state from 2000 to 2020. More studies on folate supplementation programs should be carried out.
Anemia ; Erythrocytes ; Female ; Folic Acid ; Folic Acid Deficiency/epidemiology* ; Humans ; Nutritional Status

Adult ; Aged ; Alcohol Drinking ; epidemiology ; China ; epidemiology ; Cities ; epidemiology ; Female ; Folic Acid Deficiency ; epidemiology ; Humans ; Hyperhomocysteinemia ; epidemiology ; Male ; Middle Aged ; Prevalence ; Smoking ; epidemiology ; Vitamin B 12 Deficiency ; epidemiology

OBJECTIVETo describe the distribution of plasma folate concentrations and prevalence of folate deficiency in adults aged 35 to 64 years in some areas and different seasons in China.

METHODSStudy subjects were sampled from the representative rural and urban areas in the south and north of China aged 35 to 64 years totaling 2 545, and their plasma folate concentrations were determined and analyzed.

RESULTSPlasma concentrations of folate in the southern population were significantly higher (16.9 nmol/L) than those in the north (8.3 nmol/L), and the prevalence of folate deficiency in the south (5.8%) was significantly lower than that in the north (37.1%). Plasma folate concentration varied with season either in the south or north. Plasma concentrations of folate were lower during the summer and the fall (15.0 nmol/L) than those during the winter and the spring (18.8 nmol/L) in the south, but without significant changes in the prevalence of folate deficiency in different seasons. However, the plasma folate concentrations were significantly higher during the summer and the fall (9.7 nmol/L) than those during the winter and the spring (7.1 nmol/L) in the north. And the prevalence of folate deficiency in the north was significantly higher in winter and spring (48.0%) than that in summer and fall (26.2%).

CONCLUSIONSThere existed significant difference in plasma folate concentrations in adults between varied geographic areas in China, which differed from their seasonal changes.

Adult ; China ; epidemiology ; Female ; Folic Acid ; blood ; Folic Acid Deficiency ; epidemiology ; Humans ; Male ; Middle Aged ; Rural Health ; statistics & numerical data ; Seasons ; Urban Health ; statistics & numerical data

We evaluated the prevalence of vitamin B12 deficiency and associated factors in type 2 diabetes patients using metformin. A total of 799 type 2 diabetes patients using metformin was enrolled. Vitamin B12 and folate levels were quantified by chemiluminescent enzyme immunoassay. Vitamin B12 deficiency was defined as vitamin B12 < or = 300 pg/mL without folate deficiency (folate > 4 ng/mL). The prevalence of vitamin B12 deficiency in metformin-treated type 2 diabetes patients was 9.5% (n = 76), and the mean vitamin B12 level was 662.5 +/- 246.7 pg/mL. Vitamin B12 deficient patients had longer duration of metformin use (P < 0.001) and higher daily metformin dose (P < 0.001) than non-deficient patients. Compared with daily metformin dose of < or = 1,000 mg, the adjusted odds ratio for 1,000-2,000 mg, and > or = 2,000 mg were 2.52 (95% CI, 1.27-4.99, P = 0.008) and 3.80 (95% CI, 1.82-7.92, P < 0.001). Compared with metformin use of < 4 yr, the adjusted odds ratios for 4-10 yr, and > or = 10 yr were 4.65 (95% CI, 2.36-9.16, P < 0.001) and 9.21 (95% CI, 3.38-25.11, P < 0.001), respectively. In conclusion, our study indicates that patients with type 2 diabetes treated with metformin should be screened for vitamin B12 deficiency, especially at higher dosages (> 1,000 mg) and longer durations (> or = 4 yr) of treatment.
Aged ; Area Under Curve ; Diabetes Mellitus, Type 2/complications/diagnosis/*drug therapy ; Female ; Folic Acid/blood ; Humans ; Hypoglycemic Agents/adverse effects/*therapeutic use ; Immunoassay ; Male ; Metformin/adverse effects/*therapeutic use ; Middle Aged ; Odds Ratio ; Patients ; Prevalence ; ROC Curve ; Time Factors ; Vitamin B 12/blood ; Vitamin B 12 Deficiency/diagnosis/epidemiology/*etiology