Vitamin B9 in Dark Green Vegetables: Deficiency Disorders, Bio-Availability, and Fortification Issues

Folic acid is a B complex water-soluble vitamin that is essential to humans, and its deficiency can cause problems including neural tube defects as well as heart-related diseases. An important feature of such vitamins is that they are generally not synthesized by mammalian cells and therefore must be supplied in sufficient amounts in the diet. Folate is a generic term for compounds, possessing vitamin activity similar to that of pteroylglutamic acid, and is the form of the vitamin, which is naturally present in foods. The main dietary sources of folic acid are dark green and leafy vegetables such as spinach, asparagus, romaine lettuce, broccoli, bok choy, turnip green, beet, dried or fresh beans, and peas. The amount of folate that is absorbed and utilized physiologically varies among different food sources and different chemical forms of the vitamin. About 85% of folic acid is estimated to be bioavailable; however, the bioavailability of food folate is estimated at about 50% of folic acid. Several national health authorities have introduced mandatory food fortification with synthetic folic acid, which is considered a convenient fortificant, being cost efficient in production, more stable than natural food folate, and superior in terms of bioavailability and bio-efficacy. Presently, many countries affected by diseases associated with a lack of folic acid have made it mandatory to supplement foods with the vitamin. Considering the need, several analytical procedures were standardized to determine the presence of folic acid in different food matrices. The reported methods are simple, selective, robust, and reproducible and can be used in routine analyses.

Folate, Vitamin B6 and Vitamin B12 Intake in Relation to Hyperuricemia

To assess the association between intake of folate, vitamin B6, and vitamin B12 with hyperuricemia (HU) among adults from the United States (US), we extracted relevant data from 24,975 US adults aged 20–85 years from the National Health and Nutrition Examination Survey (NHANES) in 2001–2014. All dietary intake was evaluated by 24-h dietary recalls. Multivariable logistic regression analysis was performed to explore the associations after adjustment for confounders. Compared to the lowest quintile (Q1), for males, adjusted odds ratios (ORs) of HU in Q2 to Q5 of folate (dietary folate equivalent, DFE) intake were 0.84 (95% CI, 0.73–0.96), 0.84 (0.73–0.97), 0.72 (0.62–0.84), and 0.64 (0.53–0.77), respectively (p for trend <0.0001). In females, adjusted ORs in Q2 to Q4 of folate (DFE) intake were 0.84 (95% CI, 0.71–0.99), 0.81 (0.68–0.96), and 0.82 (0.68–0.99), with a p for trend of 0.1475. Our findings indicated the intakes of total folate, folic acid, food folate, folate (DFE), vitamin B12, but not vitamin B6, were inversely related to the risk of HU in males. A lower risk of HU with higher intakes of total folate, food folate, and folate (DFE) was found in females, but with no association between intakes of folic acid, vitamin B6, B12, and the risk of HU for females.

Folate inadequacy in the diet of pregnant women

OBJECTIVE: To estimate food and dietary folate inadequacies in the diets of adult pregnant women. METHODS: A prospective study was conducted with 103 healthy pregnant adult users of the Public Health Care System of Ribeirão Preto, São Paulo, Brazil. The present study included the 82 women with complete food intake data during pregnancy, which were collected by three 24-hour dietary recalls. Food folate (folate naturally present in foods) and dietary folate (food folate plus folate from fortified wheat flour and cornmeal) inadequacies were determined, using the Estimated Average Requirement as cutoff. RESULTS: The diets of 100% and 94% of the pregnant women were inadequate in food folate and dietary folate, respectively. However, fortified foods increased the medium availability of the nutrient by 87%. CONCLUSION: The large number of pregnant women consuming low-folate diets was alarming. Nationwide population studies are needed to confirm the hypothesized high prevalence of low-folate diets among pregnant women.