Vitamin C fortification: need and recent trends in encapsulation technologies

The multifaceted role of vitamin C in human health intrudes several biochemical functions that are but not limited to antioxidant activity, homoeostasis, amino acid synthesis, collagen synthesis, osteogenesis, neurotransmitter production and several yet to be explored functions. In absence of an innate biosynthetic pathway, humans are obligated to attain vitamin C from dietary sources to maintain its optimal serum level (28 μmol/L). However, a significant amount of naturally occurring vitamin C may deteriorate due to food processing, storage and distribution before reaching to the human gastrointestinal tract, thus limiting or mitigating its disease combating activity. Literature acknowledges the growing prevalence of vitamin C deficiency across the globe irrespective of geographic, economic and population variations. Several tools have been tested to address vitamin C deficiency, which are primarily diet diversification, biofortification, supplementation and food fortification. These strategies inherit their own advantages and limitations. Opportunely, nanotechnology promises an array of delivery systems providing encapsulation, protection and delivery of susceptible compounds against environmental factors. Lack of clear understanding of the suitability of the delivery system for vitamin C encapsulation and fortification; growing prevalence of its deficiency, it is a need of the hour to develop and design vitamin C fortified food ensuring homogeneous distribution, improved stability and enhanced bioavailability. This article is intended to review the importance of vitamin C in human health, its recommended daily allowance, its dietary sources, factors donating to its stability and degradation. The emphasis also given to review the strategies adopted to address vitamin c deficiency, delivery systems adopted for vitamin C encapsulation and fortification.

Vitamin C levels in a Central-African mother-infant cohort: Does hypovitaminosis C increase the risk of enteric infections?

In the MITICA (Mother‐to‐Infant TransmIssion of microbiota in Central‐Africa) study, 48 mothers and their 50 infants were followed from delivery to 6 months between December 2017 and June 2019 in Bangui (Central‐African Republic). Blood tests and stool analyses were performed in mothers at delivery, and their offspring at birth, 11 weeks and 25 weeks. Stool cultures were performed in specific growth media for Salmonella, Shigella, E. coli, Campylobacter, Enerobacter, Vibrio cholerae, Citrobacter and Klebsiella, as well as rotavirus, yeasts and parasitological exams. The median vitamin C levels in mothers at delivery were 15.3 μmol/L (inter‐quartile‐range [IQR] 6.2–27.8 μmol/L). In infants, the median vitamin C levels at birth were 35.2 μmol/L (IQR 16.5–63.9 μmol/L). At 11 and 25 weeks, the median vitamin C levels were 41.5 μmol/L (IQR 18.7–71.6 μmol/L) and 18.2 μmol/L (IQR 2.3–46.6 μmol/L), respectively. Hypovitaminosis C was defined as seric vitamin C levels <28 μmol/L and vitamin C deficiency was defined as vitamin C levels <11 μmol/L according to the WHO definition. In mothers, the prevalence of hypovitaminosis‐C and vitamin C deficiency at delivery was 34/45 (75.6%) and 19/45 (42.2%), respectively. In infants, the prevalence of hypovitaminosis‐C and vitamin C deficiency at 6 months was 18/33 (54.6%) and 11/33 (33.3%), respectively. Vitamin C levels in mothers and infants were correlated at birth (Spearman's rho = 0.5; P value = 0.002), and infants had significantly higher levels of vitamin C (median = 35.2 μmol/L; IQR 16.5–63.9 μmol/L), compared to mothers (median = 15.3 μmol/L; IQR 6.2–27.8 μmol/L; P value <0.001). The offspring of vitamin C‐deficient mothers had significantly lower vitamin C levels at delivery (median = 18.7 μmol/L; IQR 13.3–30.7 μmol/L), compared to the offspring of non‐deficient mothers (median = 62.2 μmol/L; IQR 34.6–89.2 μmol/L; P value <0.001). Infants with hypovitaminosis‐C were at significantly higher risk of having a positive stool culture during the first 6 months of life (adjusted OR = 5.3, 95% CI 1.1; 26.1; P value = 0.038).

Global Vitamin C Status and Prevalence of Deficiency: A Cause for Concern?

Vitamin C is an essential nutrient that must be obtained through the diet in adequate amounts to prevent hypovitaminosis C, deficiency and its consequences-including the potentially fatal deficiency disease scurvy. Global vitamin C status and prevalence of deficiency has not previously been reported, despite vitamin C's pleiotropic roles in both non-communicable and communicable disease. This review highlights the global literature on vitamin C status and the prevalence of hypovitaminosis C and deficiency. Related dietary intake is reported if assessed in the studies. Overall, the review illustrates the shortage of high quality epidemiological studies of vitamin C status in many countries, particularly low- and middle-income countries. The available evidence indicates that vitamin C hypovitaminosis and deficiency is common in low- and middle-income countries and not uncommon in high income settings. Further epidemiological studies are required to confirm these findings, to fully assess the extent of global vitamin C insufficiency, and to understand associations with a range of disease processes. Our findings suggest a need for interventions to prevent deficiency in a range of at risk groups and regions of the world.

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.

Discrepancies in global vitamin C recommendations: a review of RDA criteria and underlying health perspectives

The concept of a 'recommended dietary allowance' (RDA) and similar terms describing the daily intake of essential nutrients recommended for healthy individuals is widely used by various health authorities around the world. For vitamin C, however, there remain significant discrepancies in the criteria used to establish dietary recommendations and consequently, global recommendations for daily vitamin C intake vary by more than five fold. While it appears that the scientific data underlying the recommendations are more or less the same, the interpretation differs considerably. Moreover, although a number of the assumptions used in e.g. the body pool estimates of the 1960s and 1970s have later been proven wrong and give rise to significant underestimations, these data are still used as the main support of several recommendations. Aspects that modify vitamin C requirements, such as gender, age, pregnancy, lactation, and smoking, have been taken into consideration by many but not all regulatory authorities, and are thus subject of debate. In contrast, body weight, a significant predictor of vitamin C status and requirement, has not been taken into consideration with respect to vitamin C recommendations, even in the face of the looming global obesity pandemic. The present review examines the discrepancies in vitamin C dietary recommendations of international authorities and critically discusses representative examples of criteria and the underlying health perspectives used to derive current recommended intakes of vitamin C. New biological signatures of vitamin C nutriture are also explored with regard to their potential use for future updates of dietary recommendations.

Vitamins supplementation affects the onset of preeclampsia

Preeclampsia may affect between 2-8% of all pregnancies. It seriously affects maternal health after pregnancy. This meta-analysis was performed to define the efficacy of vitamins supplementation on the risk of preeclampsia. Potential articles were systematically searched on the databases of Pubmed, Embase and Web of Science up to May 2016. Relative risk (RR) and 95% confidence intervals (95%CIs) were used to analyze the relationship of vitamins supplementation with risk of preeclampsia. Cochran Q test was used to test inter-study heterogeneity. Begg's funnel plot was adopted to assess the potential publication bias. 28 eligible studies were selected. Pooled results indicated that vitamins supplementation could reduce the risk of preeclampsia (RR = 0.74, 95%CI = 0.64-0.86). The studies with non-randomized controlled trial (RCT) analysis also suggested the significant relationship of vitamins supplementation with risk of preeclampsia (RR = 0.60, 95%CI = 0.42-0.85). However, negative results were observed in studies with RCT analysis. Subgroup analysis by vitamin type was performed among the studies with RCT analysis. The results indicated that vitamin D supplementation could significantly reduce the risk of preeclampsia (RR = 0.41, 95%CI = 0.22-0.78). Similar results were observed in the studies with multivitamins supplementation (RR = 0.69, 95%CI = 0.51-0.93). Vitamins supplementation could reduce the onset of preeclampsia.

The Paraoxonase 1 Arylesterase Activity, Total Oxidative Stress, Nitric Oxide and Vitamin C Levels in Maternal Serum, and Their Relation to Birth Weight of Newborn

AIM

Aim of this study is to find out clinical relevance of estimating PON1 arylesterase activity, total oxidative stress (TOS), nitric oxide (NO), and vitamin C levels in maternal serum for prediction of birth weight of newborn.

METHODS

We have investigated the PON1 arylesterase activity, TOS, NO, vitamin C, total protein, and albumin levels in 56 postnatal clinic patients having newborn weighing <2500 gm (low birth weight) and compared with 56 postnatal clinic patients having newborn weighing >2500 gm. Samples were collected immediately after delivery.

RESULTS

PON1 arylesterase activity levels show significant decrease in cases as compared to controls (93.27 ± 13.76 kU/l vs. 112.77 ± 9.42 kU/l). Nitric oxide (nitrate + nitrite) levels are also found to be significantly decreased in cases with respect to controls (22.89 ± 2.65 umol/l vs. 24.73 ± 3.80 umol/l). Total oxidative stress is significantly increased in cases than in control subjects (23.34 ± 2.64 μmol H2O2 equiv./l vs. ± 21.43 ± 2.47 μmol H2O2 equiv/l). Vitamin C levels are also significantly decreased in cases as compared to controls (1.23 ± 0.25 mg/dl vs. 1.34 ± 0.28 mg/dl). Positive correlation between neonatal birth weight and maternal serum PON1 arylesterase activity (r = 0.682, p < 0.05) while negative correlation is obtained between neonatal birth weight and maternal serum oxidative stress (r = -0.478, p < 0.05). Logistic regression analysis is applied for assessing predictive utility which demonstrated a significant association of birth weight with PON1 arylesterase activity (AUC = 0.960, Naglekerke's R (2) = 0.793, p < 0.05).

CONCLUSION

Decreased arylesterase activity and antioxidant vitamin C levels with increased total oxidative stress in maternal serum may be considered as the additional risk factors for the development of low birth weight newborn.

The effects of vitamin C supplementation on pre-eclampsia in Mulago Hospital, Kampala, Uganda: a randomized placebo controlled clinical trial

Background

Oxidative stress plays a role in the pathogenesis of pre-eclampsia. Supplementing women with antioxidants during pregnancy may reduce oxidative stress and thereby prevent or delay the onset pre-eclampsia. The objective of this study was to evaluate the effect of supplementing vitamin C in pregnancy on the incidence of pre-eclampsia, at Mulago hospital, Kampala, Uganda.

Methods

This was a (parallel, balanced randomization, 1:1) placebo randomized controlled trial conducted at Mulago hospital, Department of Obstetrics and Gynecology. Participants included in this study were pregnant women aged 15-42 years, who lived 15 km or less from the hospital with gestational ages between 12-22 weeks. The women were randomized to take 1000mg of vitamin C (as ascorbic acid) or a placebo daily until they delivered. The primary outcome was pre-eclamsia. Secondary outcomes were: severe pre-eclampsia, gestational hypertension, preterm delivery, low birth weight and still birth delivery. Participants were 932 pregnant women randomized into one of the two treatment arms in a ratio of 1:1. The participants, the care providers and those assessing the outcomes were blinded to the study allocation.

Results

Of the 932 women recruited; 466 were randomized to the vitamin and 466 to the placebo group. Recruitment of participants was from November 2011 to June 2012 and follow up was up to January 2013. Outcome data was available 415 women in the vitamin group and 418 women in the placebo group.

There were no differences in vitamin and placebo groups in the incidence of pre-eclampsia (3.1% versus 4.1%; RR 0.77; 95% CI: 0.37-1.56), severe pre-eclampsia (1.2% versus 1.0%; RR 1.25; 95% CI: 0.34-4.65), gestational hypertension(7.7% versus 11.5%; RR 0.67; 95% CI: 0.43-1.03), preterm delivery (11.3% versus 12.2%; RR 0.92; 95% CI: 0.63-1.34), low birth weight (11.1% versus 10.3%; RR 1.07; 95% CI: 0.72-1.59) and still birth delivery (4.6% versus 4.5%; RR 1.01; 95% CI: 0.54-1.87).

Conclusions

Supplementation with vitamin C did not reduce the incidence of pre-eclampsia nor did it reduce the adverse maternal or neonatal outcomes. We do not recommend the use of vitamin C in pregnancy to prevent pre-eclampsia.

Trial registration

This study was registered at the Pan African Clinical Trial Registry, PACTR201210000418271 on 25^th October 2012.