Factors Affecting Vitamin C Status and Prevalence of Deficiency: A Global Health Perspective.

A recent review of global vitamin C status has indicated a high prevalence of deficiency, particularly in low- and middle-income countries, as well as in specific subgroups within high-income countries. Here, we provide a narrative review of potential factors influencing vitamin C status globally. The in vivo status of vitamin C is primarily affected by dietary intake and supplement use, with those who supplement having a higher mean status and a lower prevalence of deficiency. Dietary intake can be influenced by cultural aspects such as traditional cooking practices and staple foods, with many staple foods, such as grains, contributing negligible vitamin C to the diet. Environmental factors can also affect vitamin C intake and status; these include geographic region, season, and climate, as well as pollution, the latter partly due to enhanced oxidative stress. Demographic factors such as sex, age, and race are known to affect vitamin C status, as do socioeconomic factors such as deprivation, education and social class, and institutionalization. Various health aspects can affect vitamin C status; these include body weight, pregnancy and lactation, genetic variants, smoking, and disease states, including severe infections as well as various noncommunicable diseases such as cardiovascular disease and cancer. Some of these factors have changed over time; therefore, we also explore if vitamin C status has shown temporal changes. Overall, there are numerous factors that can affect vitamin C status to different extents in various regions of the world. Many of these factors are not taken into consideration during the setting of global dietary intake recommendations for vitamin C.

Vegetable and fruit consumption, education and plasma vitamin C concentration in Russian and Finnish Karelia, 1992-2002.

OBJECTIVE: To examine (i) whether the consumption of fresh vegetables, fruit and berries is associated with plasma vitamin C concentration and (ii) educational differences in plasma vitamin C concentration in two neighbouring areas in Russia and Finland. DESIGN: Cross-sectional risk factor surveys in 1992, 1997 and 2002. Logistic regression analysis was applied to examine the associations of consumption of selected foods and education with plasma vitamin C concentration. SETTING: District of Pitkäranta in the Republic of Karelia, Russia and North Karelia, Finland. SUBJECTS: Adults aged 25-64 years: 579 men and 612 women in Pitkäranta; 974 men and 642 women in North Karelia. RESULTS: The plasma vitamin C concentration was strikingly low in Pitkäranta, Russia across the study years. During the 10 years of monitoring, the mean plasma vitamin C concentration among men ranged from 2·5 to 8·0 µmol/l in Pitkäranta, Russia and from 27·1 to 53·9 µmol/l in North Karelia, Finland. In both areas, daily consumption of fruit was most strongly associated with plasma vitamin C, while the association of fresh vegetable consumption with plasma vitamin C was less consistent. Consumption of berries was less important in explaining plasma vitamin C. In Pitkäranta, the plasma vitamin C concentration was lower among respondents in the lowest education group. CONCLUSIONS: Differences in the consumption of fresh vegetables and fruit resulted in notable differences in vitamin C status between Pitkäranta and North Karelia in spring. In comparative settings, knowledge of local food culture and validation pilots are important before conducting large population surveys.

Several 'problem nutrients' are identified in complementary feeding of Guatemalan infants with continued breastfeeding using the concept of 'critical nutrient density'.

BACKGROUND/OBJECTIVES: The World Health Organization (WHO) recommends nutritionally adequate complementary feeding (CF) through the introduction of indigenous foodstuffs and local foods while breastfeeding for at least 2 years. To determine the adequacy of the contribution of CF to the diets of Guatemalan infants at the 7th-12th month of life receiving high-intensity continued breastfeeding. SUBJECTS/METHODS: Critical nutrient densities for CF were modelled using age- and sex-specific energy and protein requirements assuming children to be at the 50th weight percentile of local peers and 15th weight percentiles of the 2006 WHO standards. Nutrient requirements for the total diet were determined using the recommended nutrient intakes. Breast milk was assumed to provide 75% of total energy at the 7th-9th month and 50% at the 10th-12th month. Gaps between computed critical nutrient densities and the CF consumption of 128 Guatemalan infants based on data collected by means of three nonconsecutive 24-h quantitative intake recalls were examined. Locally consumed foods with nutrient densities above the modelled critical densities were identified. RESULTS: Observed non-breast milk complementation would result in total diets providing inadequate nutrient density for vitamin A, niacin and vitamin C in some age groups. Major gaps for calcium, iron and zinc were ubiquitous across all groups. Few foods commonly consumed among Guatemalan infants had adequate densities of 'problem nutrients'. CONCLUSIONS: The critical nutrient density concept is useful to evaluate the nutrient adequacy of the infant's diet. Fortified foods are essential sources of the main 'problem nutrients', namely calcium, iron and zinc, given that natural sources are scarce.

Nutritional status of 8- to 12-year-old children with height below or at 25th percentile associated with height in the Seoul metropolitan area.

BACKGROUND: Childhood is the best time to establish healthful dietary habits through adulthood. However, as of yet, there is relatively little research on the nutritional status of children with low height. This study aimed to evaluate the nutritional status of school-aged children with low height. METHODS: This study was implemented in the Seoul metropolitan area with 8- to 12-year-old Korean children (n = 93) who fall below the 25th percentile (<= P25) for height. Nutritional status was assessed using anthropometry and dietary assessment. Dietary assessment was carried out using a 24-hour recall on a typical and quantitative food frequency questionnaire. The Pearson' s correlation analysis was conducted to determine associations between height and nutrient intake. RESULTS: The mean percentiles of height were 19.5(th) for boys, and 19.0(th) for girls, respectively. Nutrients ingested below the Estimated Average Requirement (EAR) of the Dietary Reference Intakes for Koreans (KDRIs), considered inadequate, were folic acid, calcium, vitamin C, and iron. Significant differences between recommended and consumed servings of food groups were observed in the meat, fish, egg, and legume group (p = 0.039), vegetable group (p < 0.001), and fruit group (p = 0.044). The height percentiles of the subjects were negatively correlated with calories derived from carbohydrates (p < 0.001). CONCLUSIONS: School-aged children living in the Seoul metropolitan area, with height <= P25, consumed inadequate nutrients and insufficient food groups, which may put the children in a low height percentile. More efforts to provide education on adequate dietary intake and to monitor the nutritional status of children are needed to improve dietary adequacy based on food groups and to increase the growth of children with low height.

Vitamin C deficiency in a population of young Canadian adults.

A cross-sectional study of the 979 nonsmoking women and men aged 20-29 years who participated in the Toronto Nutrigenomics and Health Study from 2004 to 2008 was conducted to determine the prevalence of serum ascorbic acid (vitamin C) deficiency and its association with markers of chronic disease in a population of young Canadian adults. High performance liquid chromatography was used to determine serum ascorbic acid concentrations from overnight fasting blood samples. A 1-month, 196-item food frequency questionnaire was used to assess dietary intakes. Results showed that 53% of subjects had adequate, 33% had suboptimal, and 14% had deficient levels of serum ascorbic acid. Subjects with deficiency had significantly higher measurements of mean C-reactive protein, waist circumference, body mass index, and blood pressure than did subjects with adequate levels of serum ascorbic acid. The odds ratio for serum ascorbic acid deficiency was 3.43 (95% confidence interval: 2.14, 5.50) for subjects who reported not meeting the recommended daily intake of vitamin C compared with those who did. Results suggest that 1 of 7 young adults has serum ascorbic acid deficiency, in part, because of unmet recommended dietary intakes. Furthermore, serum ascorbic acid deficiency is associated with elevated markers of chronic disease in this population of young adults, which may have long-term adverse health consequences.

Gastric juice ascorbic acid is related to Helicobacter pylori infection but not ethnicity.

BACKGROUND: Maori and Pacific Island ethnic groups in New Zealand have a high risk for gastric cancer. Low levels of gastric juice ascorbic acid (vitamin C) have been suggested to be a risk factor for gastric cancer. Previous studies have shown that gastric juice ascorbic acid may be independently associated with both ethnicity and Helicobacter pylori infection. This study aimed to examine the interrelationship between H. pylori and ethnicity in New Zealand. METHODS: Gastric juice was collected into 70% perchloric acid preservative and stored at -80 degrees C. Ascorbic acid was analysed by high-performance liquid chromatography using ion-pair chromatography and electrochemical detection. Inflammation and atrophy was graded from biopsies from multiple sites in the antrum and body. Gastric juice was collected from 89 patients during routine endoscopy. RESULTS: There was a wide range of measured gastric juice ascorbic acid from 0.001 to 410 microg/mL. The median concentration of ascorbic acid for H. pylori-negative patients was 1.78 microg/mL (n = 57) and 0.12 microg/mL (n = 32) for H. pylori-positive patients (P = 0.001). Gastric juice ascorbic acid concentration was not associated with age, endoscopic diagnosis or intestinal metaplasia, but was significantly associated with the degree of acute inflammation (P = 0.01) and the presence of atrophy (P = 0.04). The median ascorbic acid concentration for European patients was 0.92 microg/mL (n = 44) and 0.09 microg/mL (n = 38) for Maori and Pacific Island ethnic groups combined (P = 0.1). Multiple step-wise regression analysis showed that only H. pylori infection was a significant factor for predicting ascorbic acid concentrations (r2 = 0.12). CONCLUSIONS: This study has confirmed that gastric juice ascorbic acid concentration is lower in the presence of H. pylori infection.