Folate food source, usual intake, and folate status in Korean adults

Main sources and predictive factors of folate intake in female university students

OBJECTIVE

The study aimed to identify the main folate sources and examine socio-demographic and lifestyle determinants influencing folate intake among 1410 women aged 18 to 39.

METHODS

Data were collected using a self-administered health and lifestyle questionnaire and a 5-d dietary record method. To assess folate intake in relation to the dietary reference intakes, the probability approach was used. Folate intake determinants were identified using multivariate-adjusted logistic regression models; odds ratios (ORs) with 95% confidence intervals (95% CIs).

RESULTS

The average total folate intake among women was 311 ± 144 µg/day dietary folate equivalents. Vegetables (30.7%) and cereals (22.6%) were the most important folate sources. Foods fortified with folic acid were consumed by 20.6% of women, dietary supplements by 7.2%. More than half of the participants (55%) had a high probability of inadequate folate intake. The predictors of being in the highest tertile of folate intake (>303 versus <225 µg) were: physical activity (high versus low; OR: 2.97, 95% CI: 1.77-4.97), nutritional knowledge (high versus low; OR: 5.32, 95% CI: 2.82-10.1), following a vegetarian diet (yes versus no; OR: 6.13; 95% CI: 2.79-13.5), daily number of meals (≥5 versus ≤3; OR: 4.17, 95% CI: 2.38-7.32), excluding/including some foods (yes versus no; OR: 2.47; 95% CI: 1.41-4.31) and energy intake (3rd versus 1st tertile; OR:17.4, 95% CI: 11.1-27.4).

CONCLUSION

Identifying factors associated with a higher intake of folate may be helpful in shaping public health nutrition policy. It allows the design of effective nutrition education programs to promote increased intake of folate in subgroups at risk of deficiency.

Folate, vitamin B12, and homocysteine status in the Korean population: data from the 2013-2015 Korea National Health and Nutrition Examination Survey

OBJECTIVES

We aimed to assess the serum folate, vitamin B12, and homocysteine status in Korean adolescents and adults using national data.

METHODS

Blood samples were collected from participants aged ≥10 years in the Korea National Health and Nutrition Examination Survey 2013-2015. The stored serum samples were used to measure folate, vitamin B12, and homocysteine concentrations. A total of 8,016 participants were included in this analysis. Unweighted descriptive statistics and adjusted geometric means of the B vitamins and homocysteine concentrations were estimated.

RESULTS

Females had higher serum folate and vitamin B12 concentrations and lower serum homocysteine concentrations than males. Folate deficiency (<6.8 nmol/L) and hyperhomocysteinemia (>15 μmol/L) were found in 8.6% and 11.8% of males, respectively. Approximately 3% of males had low or marginally low vitamin B12 status (≤221 pmol/L). Folate and vitamin B12 deficiencies and hyperhomocysteinemia were found in <2% of females. Suboptimal folate status was prevalent among adolescents and young adults, while suboptimal vitamin B12 status and hyperhomocysteinemia were relatively higher in older adults. Adjusted mean homocysteine concentrations were sharply decreased from the first to second decile of serum folate in males.

CONCLUSIONS

In the Korean population, the proportion of males who achieved desirable folate and homocysteine concentrations were lower than those of females. Although most Koreans have adequate vitamin B12, a suboptimal folate status is common, particularly among adolescents and young adults. These findings could establish a foundation for public health initiatives aimed at improving folate levels in the Korean population.

Usual intake of one-carbon metabolism nutrients in a young adult population aged 19-30 years: a cross-sectional study

One-carbon nutrients play an important role in epigenetic mechanisms and cellular methylation reactions. Inadequate intake of these nutrients is linked to metabolic perturbations, yet the current intake levels of these nutrients have rarely been studied in Asia. This cross-sectional study surveyed the usual dietary intake of one-carbon nutrients (folate, choline and vitamins B2, B6 and B12) among Thai university students aged 19-30 years (n 246). Socioeconomic background, health information, anthropometric data and 24-h dietary recall data were collected. The long-term usual intake was estimated using the multiple-source method. The average usual intake levels for men and women were (mean ± sd) 1⋅85 ± 0⋅95 and 2⋅42 ± 8⋅7 mg/d of vitamin B2, 1⋅96 ± 1⋅0 and 2⋅49 ± 8⋅7 mg/d of vitamin B6, 6⋅20 ± 9⋅5 and 6⋅28 ± 12 μg/d of vitamin B12, 195 ± 154 and 155 ± 101 μg dietary folate equivalent/d of folate, 418 ± 191 and 337 ± 164 mg/d of choline, respectively. Effect modification by sex was observed for vitamin B2 (P-interaction = 0⋅002) and choline (P-interaction = 0⋅02), where every 1 mg increase in vitamin B2 and 100 mg increase in choline intake were associated with a 2⋅07 (P = 0⋅01) and 0⋅81 kg/m² (P = 0⋅04) lower BMI, respectively, in men. The study results suggest that Thai young adults meet the recommended levels for vitamins B2, B6 and B12. The majority of participants had inadequate folate intake and did not achieve recommended intake levels for choline. The study was approved by the Ethics Committee at the Faculty of Medicine, Chiang Mai University. This trial was registered at www.thaiclinicaltrials.gov (TCTR20210420007).

Preoperative Nutritional Deficiencies in Bariatric Surgery Candidates in Korea

BACKGROUND

All bariatric surgical procedures may compromise the nutritional status of patients, but nutritional deficiencies vary by region and culture. However, there are no preoperative nutritional guidelines for bariatric patients in East Asia. Here, we aimed to evaluate the preoperative nutritional status of East Asian bariatric surgical patients.

METHODS

We performed a retrospective cohort study of 215 consecutive patients who underwent bariatric surgery between January and December 2019 at a single tertiary institution in Korea. Medical background evaluation, anthropometric measurements, and laboratory tests were performed before surgery.

RESULTS

Vitamin D deficiency was identified in 80.0% of participants and 13.8% had insufficiency. The prevalence of vitamin D deficiency or insufficiency and the mean vitamin D concentration did not significantly differ between the sexes. Vitamin B1 (thiamine) deficiency was the second most common deficiency (18.3%), followed by folate (14.2%), iron (11.8%), and zinc (7.6%) deficiencies. The prevalence of anemia did not significantly differ between the sexes (1.3% in men vs. 7.4% in women, p=0.10), but the prevalence of iron deficiency was significantly higher in women (1.3% vs. 17.9%, p<0.001). The prevalences of copper (2.3%) and selenium (3.2%) deficiencies were low, and none of the participants had vitamin B12 or magnesium deficiency.

CONCLUSION

There were high prevalences of vitamin D, folate, vitamin B1, and iron deficiencies in bariatric patients in Korea. Nutritional deficiencies should be corrected prior to surgery to prevent subsequent further depletion. Routine analysis of vitamin B12, magnesium, copper, and selenium before surgery should be considered and studied in more detail.

Improving sleep disturbances in obesity by nutritional strategies: review of current evidence and practical guide

Over the past decades, there has been an increase in overweight and obesity worldwide rates in both in adult and children. In parallel, it has been reported a worsening of sleep duration and quality. Some studies have shown an association between obesity and sleep disturbances (SD) vice versa, subjects with obesity have a greater risk of SD. As well as SD influences diet, also food choices have been shown to influence various sleep-related variables, such as duration and quality. For this reason, nutrition could represent an important tool not only to lose weight but also to improve sleep in patients with obesity and sleep disturbances. Thus, the aim of this review is to provide an overview of the studies that assessed the association between obesity and SD and vice versa, highlighting possible nutritional advices as a tool to improve sleep in patients with obesity and sleep disturbances.

High Serum Folate Concentration Is Associated with Better Lung Function in Male Chronic Obstructive Pulmonary Disease Patients Who Are Current Smokers: Analysis of Nationwide Population-Based Survey

Folate, folic acid, has a role in mitigating inflammatory reactions in the human body. This study aimed to evaluate the association of serum folate levels with lung function in chronic obstructive pulmonary disease (COPD) patients. Of the 8149 participants of the 2016 Korean National Health and Nutrition Examination Survey (KNHANES), 311 subjects (192 males and 119 females) having COPD defined by the lower fifth percentile of the reference population were selected. Pearson's correlation coefficient was used to investigate the relationship between serum folate level and lung function measurements. The association between the serum folate level and lung function in patients with COPD was evaluated using multivariable linear regression analysis after adjustment for age, sex, height, high sensitivity C-reactive protein, total calorie intake, residence, smoking status and smoking pack-years, education, and household income. The serum folate level showed a positive correlation with the predicted percentage of forced expiratory volume in one second (FEV₁%). In males, a trend for a positive correlation with serum folate level was observed in predicted FEV₁%, FEV₁ value, predicted percentage of forced vital capacity (FVC%), FVC value, and peak expiratory flow (PEF). No significant correlation between the serum folate level and lung function in females was observed. In the multivariable linear regression model, the serum folate level was associated with an increase in predicted FEV1%, FEV₁ value, predicted FVC%, FVC value, and PEF; however, the significance was only observed in males, especially among current smokers. High serum folate level was positively associated with lung function measurements in male COPD patients who were current smokers. Further longitudinal studies are needed to elucidate the underlying mechanisms.

Normal-But-Low Serum Folate Levels and the Risks for Cognitive Impairment

OBJECTIVE

This study aimed to examine the association between normal-but-low folate levels and cognitive function in the elderly population using a prospective cohort study.

METHODS

We analyzed 3,910 participants whose serum folate levels were within the normal reference range (1.5-16.9 ng/mL) at baseline evaluation in the population-based prospective cohort study named the "Korean Longitudinal Study on Cognitive Aging and Dementia." The association between baseline folate quartile categories and baseline cognitive disorders [mild cognitive impairment (MCI) or dementia] was examined using binary logistic regression analysis adjusting for confounding variables. The risks of incident MCI and dementia associated with the decline of serum folate level during a 4-year follow-up period were examined using multinomial logistic regression analysis.

RESULTS

The lowest quartile group of serum folate (≥1.5, ≤5.9 ng/mL) showed a higher risk of cognitive disorders than did the highest quartile group at baseline evaluation (odds ratio 1.314, p=0.012). Over the 4 years of follow-up, the risk of incident dementia was 2.364 times higher among subjects whose serum folate levels declined from the 2nd-4th quartile group to the 1st quartile than among those for whom it did not (p=0.031).

CONCLUSION

Normal-but-low serum folate levels were associated with the risk of cognitive disorders in the elderly population, and a decline to normal-but-low serum folate levels was associated with incident dementia. Maintaining serum folate concentration above 5.9 ng/mL may be beneficial for cognitive status.

An appraisal of folates as key factors in cognition and ageing-related diseases

Folic acid (FA) is often consumed as a food supplement and can be found in fortified staple foods in various western countries. Even though FA supplementation during pregnancy is known to prevent severe congenital anomalies in the developing child (e.g., neural tube defects), much less is known about its influence on cognition and neurological functioning. In this review, we address the advances in this field and situate how folate intake during pregnancy, postnatal life, adulthood and in the elderly affects cognition. In addition, an association between folate status and ageing, dementia and other neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis is discussed. While its role in the incidence and severity of these diseases is becoming apparent, the underlying action of folates and related metabolites remains elusive. Finally, the potential of FA as a nutraceutical has been proposed, although the efficacy will highly depend on the interplay with other micronutrients, the disease stage and the duration of supplementation. Hence, the lack of consistent data urges for more animal studies and (pre)clinical trials in humans to ascertain a potential beneficial role for folates in the treatment or amelioration of cognitive decline and ageing-related disorders.