Impact of oral vitamin D supplementation on serum 25-hydroxyvitamin D levels in oncology

Background  

Serum 25-hydroxyvitamin D [25(OH)D] is the major circulating form of vitamin D and a standard indicator of vitamin D status. Emerging evidence in the literature suggests a high prevalence of suboptimal vitamin D (as defined by serum 25(OH)D levels of <32 ng/ml) as well as an association between lower serum levels and higher mortality in cancer. We investigated the effect of oral vitamin D supplementation as a means for restoring suboptimal levels to optimal levels in cancer.     

Vitamin C and Vitamin E in Prevention of Nonalcoholic Fatty Liver Disease (NAFLD) in Choline Deficient Diet Fed Rats

Aim  

Oxidative stress has been implicated in the pathogenesis of Nonalcoholic Fatty Liver Disease (NAFLD). Vitamin C and vitamin E are known to react with reactive oxygen species (ROS) blocking the propagation of radical reactions in a wide range of oxidative stress situations. The potential therapeutic efficacy of antioxidants in NAFLD is unknown. The aim of this study was to evaluate the role of antioxidant drugs (vitamin C or vitamin E) in its prevention.     

Development of a healthy biscuit: an alternative approach to biscuit manufacture

Objective  

Obesity (BMI >30) and related health problems, including coronary heart disease (CHD), is without question a public health concern. The purpose of this study was to modify a traditional biscuit by the addition of vitamin B₆, vitamin B₁₂, Folic Acid, Vitamin C and Prebiotic fibre, while reducing salt and sugar.     

The positive impact of red palm oil in school meals on vitamin A status: study in Burkina Faso

Background  

Vitamin A (VA) deficiency is widespread in sub-Saharan Africa and school-age children are a vulnerable group. In Burkina Faso, the production and consumption of red palm oil (RPO) is being promoted as a food supplement for VA. The objective of the study was to assess the impact on serum retinol of adding RPO to school lunch in two test zones of Burkina Faso.     

Vitamin A deficiency and inflammatory markers among preschool children in the Republic of the Marshall Islands

Background  

The exclusion of individuals with elevated acute phase proteins has been advocated in order to improve prevalence estimates of vitamin A deficiency in surveys, but it is unclear whether this will lead to sampling bias. The purpose of the study was to determine whether the exclusion of individuals with elevated acute phase proteins is associated with sampling bias and to characterize inflammation in children with night blindness.     

Assessment of soy phytoestrogens' effects on bone turnover indicators in menopausal women with osteopenia in Iran: a before and after clinical trial

Background  

Osteoporosis is the gradual declining in bone mass with age, leading to increased bone fragility and fractures. Fractures in hip and spine are known to be the most important complication of the disease which leads in the annual mortality rate of 20% and serious morbidity rate of 50%. Menopause is one of the most common risk factors of osteoporosis. After menopause, sex hormone deficiency is associated with increased remodeling rate and negative bone balance, leading to accelerated bone loss and micro-architectural defects, resulting into increased bone fragility.     

Beziehungen von Vitamin E zur Arteriosklerose

Relationship between Vitamin E and Arteriosclerosis Vitamin E deficiency in animals can lead to arteriosclerotic changes of blood vessels. Antioxidant vitamins A and E are, therefore, part of an important biological defense system. In this paper we describe effects of antioxidant vitamins on the synthesis of prostacyclin (PGI₂) by cultured human endothelial cells and on the mortality of middle-aged men due to ischemic heart diseases. In vitro studies on the induced prostacyclin (PGI₂) synthesis of cultured human endothelial cells from umbilical cord veins show an increased release of PGI₂ in the presence of vitamin E (all-rac-α-tocopherol) and trolox (rac-2-carboxy-6-hydroxy-2,5,7,8-tetramethylchroman). Cross-cultural epidemiological studies on different male populations (age 40 – 49 years, N = 12) throughout Europe show a statistically significant inverse correlation between the status of antioxidant vitamins A and E in plasma and the rate of mortality due to ischemic heart disease. In conclusion, the results of both the in vitro studies and the epidemiological surveys are consistent with the interpretation that antioxidant vitamins reduce damage induced by peroxidation of important biological structures, and hence limit the development of arteriosclerosis.     

Comparison of two modes of vitamin B<Subscript>12</Subscript>supplementation on neuroconduction and cognitive function among older people living in Santiago,Chile: a cluster randomized controlled trial. a study protocol [ISRCTN 02694183]

Background

Older people have a high risk of vitamin B₁₂ deficiency; this can lead to varying degrees of cognitive and neurological impairment. CBL deficiency may present as macrocytic anemia, subacute combined degeneration of the spinal cord, or as neuropathy, but is often asymptomatic in older people. Less is known about subclinical vitamin B12 deficiency and concurrent neuroconduction and cognitive impairment. A Programme of Complementary Feeding for the Older Population (PACAM) in Chile delivers 2 complementary fortified foods that provide approximately 1.4 μg/day of vitamin B12 (2.4 μg/day elderly RDA). The aim of the present study is to assess whether supplementation with vitamin B12 will improve neuroconduction and cognitive function in older people who have biochemical evidence of vitamin B12 insufficiency in the absence of clinical deficiency.

Methods

We designed a cluster double-blind placebo-controlled trial involving community dwelling people aged 70-79 living in Santiago, Chile. We randomized 15 clusters (health centers) involving 300 people (20 per cluster). Each cluster will be randomly assigned to one of three arms: a) a 1 mg vitamin B12 pill taken daily and a routine PACAM food; b) a placebo pill and the milk-PACAM food fortified to provide 1 mg of vitamin B12; c) the routine PACAM food and a placebo pill.The study has been designed as an 18 month follow up period. The primary outcomes assessed at baseline, 4, 9 and 18 months will be: serum levels of vitamin B12, neuroconduction and cognitive function.

Conclusions

In view of the high prevalence of vitamin B12 deficiency in later life, the present study has potential public health interest because since it will measure the impact of the existing program of complementary feeding as compared to two options that provide higher vitamin B12 intakes that might potentially may contribute in preserving neurophysiologic and cognitive function and thus improve quality of life for older people in Chile.

Trial registration

ISRCTN: ISRCTN02694183

     

Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women

Background

Vitamin K₂ contributes to bone and cardiovascular health. Therefore, two vitamin K₂ homologues, menaquinone-4 (MK-4) and menaquinone-7 (MK-7), have been used as nutrients by the food industry and as nutritional supplements to support bone and cardiovascular health. However, little is known about the bioavailability of nutritional MK-4. To investigate MK-4 and MK-7 bioavailability, nutritional doses were administered to healthy Japanese women.

Findings

Single dose administration of MK-4 (420 ??g; 945 nmol) or MK-7 (420 ??g; 647 nmol) was given in the morning together with standardized breakfast. MK-7 was well absorbed and reached maximal serum level at 6 h after intake and was detected up to 48 h after intake. MK-4 was not detectable in the serum of all subjects at any time point. Consecutive administration of MK-4 (60 ??g; 135 nmol) or MK-7 (60 ??g; 92 nmol) for 7 days demonstrated that MK-4 supplementation did not increase serum MK-4 levels. However, consecutive administration of MK-7 increased serum MK-7 levels significantly in all subjects.

Conclusions

We conclude that MK-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels. MK-7, however significantly increases serum MK-7 levels and therefore may be of particular importance for extrahepatic tissues.     

Major reduction of malaria morbidity with combined vitamin A and zinc supplementation in young children in Burkina Faso: a randomized double blind trial

Background  

Vitamin A and zinc are crucial for normal immune function, and may play a synergistic role for reducing the risk of infection including malaria caused by Plasmodium falciparum.     

Role of Vitamin K in Chronic Kidney Disease: A Focus on Bone and Cardiovascular Health

Chronic kidney disease (CKD) is commonly associated with vitamin K deficiency. Some of the serious complications of CKD are represented by cardiovascular disease (CVD) and skeletal fragility with an increased risk of morbidity and mortality. A complex pathogenetic link between hormonal and ionic disturbances, bone tissue and metabolism alterations, and vascular calcification (VC) exists and has been defined as chronic kidney disease–mineral and bone disorder (CKD-MBD). Poor vitamin K status seems to have a key role in the progression of CKD, but also in the onset and advance of both bone and cardiovascular complications. Three forms of vitamin K are currently known: vitamin K1 (phylloquinone), vitamin K2 (menaquinone), and vitamin K3 (menadione). Vitamin K plays different roles, including in activating vitamin K-dependent proteins (VKDPs) and in modulating bone metabolism and contributing to the inhibition of VC. This review focuses on the biochemical and functional characteristics of vitamin K vitamers, suggesting this nutrient as a possible marker of kidney, CV, and bone damage in the CKD population and exploring its potential use for promoting health in this clinical setting. Treatment strategies for CKD-associated osteoporosis and CV disease should include vitamin K supplementation. However, further randomized clinical studies are needed to assess the safety and the adequate dosage to prevent these CKD complications.     

Vitamin C and Heart Health: A Review Based on Findings from Epidemiologic Studies

Vitamin C is a powerful dietary antioxidant that has received considerable attention in the literature related to its possible role in heart health. Although classical vitamin C deficiency, marked by scurvy, is rare in most parts of the world, some research has shown variable heart disease risks depending on plasma vitamin C concentration, even within the normal range. Furthermore, other studies have suggested possible heart-related benefits to vitamin C taken in doses beyond the minimal amounts required to prevent classically defined deficiency. The objective of this review is to systematically review the findings of existing epidemiologic research on vitamin C and its potential role in cardiovascular disease (CVD). It is well established that vitamin C inhibits oxidation of LDL-protein, thereby reducing atherosclerosis, but the cardiovascular outcomes related to this action and other actions of vitamin C are not fully understood. Randomized controlled trials as well as observational cohort studies have investigated this topic with varying results. Vitamin C has been linked in some work to improvements in lipid profiles, arterial stiffness, and endothelial function. However, other studies have failed to confirm these results, and observational cohort studies are varied in their findings on the vitamin’s effect on CVD risk and mortality. Overall, current research suggests that vitamin C deficiency is associated with a higher risk of mortality from CVD and that vitamin C may slightly improve endothelial function and lipid profiles in some groups, especially those with low plasma vitamin C levels. However, the current literature provides little support for the widespread use of vitamin C supplementation to reduce CVD risk or mortality.     

Zinc and vitamin A supplementation fails to reduce sputum conversion time in severely malnourished pulmonary tuberculosis patients in Indonesia

Background  

A previous study showed that combination of zinc and vitamin A reduced sputum conversion time in pulmonary tuberculosis (TB) patients.     

The effects of oral iron supplementation on cognition in older children and adults: a systematic review and meta-analysis

Background  

In observational studies anaemia and iron deficiency are associated with cognitive deficits, suggesting that iron supplementation may improve cognitive function. However, due to the potential for confounding by socio-economic status in observational studies, this needs to be verified in data from randomised controlled trials (RCTs).     

Dityrosine Crosslinking of Collagen and Amyloid-β Peptides Is Formed by Vitamin B12 Deficiency-Generated Oxidative Stress in Caenorhabditis elegans

(1) Background: Vitamin B₁₂ deficiency in Caenorhabditis elegans results in severe oxidative stress and induces morphological abnormality in mutants due to disordered cuticle collagen biosynthesis. We clarified the underlying mechanism leading to such mutant worms due to vitamin B₁₂ deficiency. (2) Results: The deficient worms exhibited decreased collagen levels of up to approximately 59% compared with the control. Although vitamin B₁₂ deficiency did not affect the mRNA expression of prolyl 4-hydroxylase, which catalyzes the formation of 4-hydroxyproline involved in intercellular collagen biosynthesis, the level of ascorbic acid, a prolyl 4-hydroxylase coenzyme, was markedly decreased. Dityrosine crosslinking is involved in the extracellular maturation of worm collagen. The dityrosine level of collagen significantly increased in the deficient worms compared with the control. However, vitamin B₁₂ deficiency hardly affected the mRNA expression levels of bli-3 and mlt-7, which are encoding crosslinking-related enzymes, suggesting that deficiency-induced oxidative stress leads to dityrosine crosslinking. Moreover, using GMC101 mutant worms that express the full-length human amyloid β, we found that vitamin B₁₂ deficiency did not affect the gene and protein expressions of amyloid β but increased the formation of dityrosine crosslinking in the amyloid β protein. (3) Conclusions: Vitamin B₁₂-deficient wild-type worms showed motility dysfunction due to decreased collagen levels and the formation of highly tyrosine-crosslinked collagen, potentially reducing their flexibility. In GMC101 mutant worms, vitamin B₁₂ deficiency-induced oxidative stress triggers dityrosine-crosslinked amyloid β formation, which might promote its stabilization and toxic oligomerization.     

Vitamin A status of pregnant women assessed by a biochemical indicator and a simplified Food Frequency Questionnaire

The aim of this study was to compare plasma concentrations of vitamin A in 710 women after delivery, with a simplified Food Frequency Questionnaire (FFQ). Vitamin A was determined in plasma, by HPLC. The FFQ included 55 foods, and was based on the typical diet of the low socioeconomic families in the Southeast of Brazil. For calculation purposes, first were identified all potential sources of retinol and carotenoids; the portion sizes being assigned to each food item on the basis of a previous study in the same area. Daily, weekly and monthly frequencies of consumption of foods with high, moderate and low concentrations of vitamin A were grouped according to the IVACG recommendations (1) in usual pattern of food consumption (UPF) scores. Pregnant women were allocated by these scores in 3 different categories (high, moderate and low) according to their risk of developing vitamin A deficiency. The categories of risk were based on the safe level of vitamin A intake of 800 RE/day (5600 RE/week) (7) and the basal requirement of 370 RE/day for pregnant women (8). 1.3% of the women had plasma concentrations of vitamin A < or = 0.70 mumol/l, 10.2% between 0.71-1.05 mumol/l and 88.5% > 1.05 mumol/l. According to the score categories, 49.5% of the women were at low risk for vitamin A deficiency, and 50.5% were at moderate risk. There was a weak statistically significant correlation between the plasma concentrations of vitamin A and the score categories (r = 0.11; p = 0.005). Our results indicate that the FFQ does not provide a very precise information on vitamin A status, probably because of the day to day variation in vitamin A intake, and the insensitivity of plasma concentrations to consumption of vitamin A. However, by using a simple score based on the FFQ, we were able to predict that the majority of the mothers were not at high risk for vitamin A deficiency.     

Vitamin D Deficiency Attenuates Acute Alcohol-Induced Hepatic Lipid Accumulation in Mice

Vitamin D deficiency has been frequently reported in chronic liver disease. However, its influence on hepatic lipid accumulation in alcoholic liver disease remains unclear. The present study investigated the effects of vitamin D deficiency on acute alcohol-induced hepatic lipid metabolism in mice. Mice were fed with vitamin D deficient diet, in which vitamin D was depleted for 12 weeks to establish an animal model of vitamin D deficiency. Some mice were administered a single gavage of alcohol (4 g/kg bodyweight) before they were euthanized. Results show that feeding mice with vitamin D deficient diet did not induce hepatic lipid accumulation. In contrast, vitamin D deficiency markedly reduced alcohol-induced triacylglycerol (TAG) content and prevented hepatic lipid accumulation. Moreover, vitamin D deficiency significantly attenuated alcohol-induced sterol-regulated element-binding protein (SREBP)-1c activation, which regulates genes for hepatic fatty acid (FA) and TAG synthesis, and the expression of its target genes fatty acid synthase (Fasn) and acetyl-coenzyme- A carboxylase (Acc). In addition, vitamin D deficiency alleviated alcohol-induced downregulation of hepatic nuclear peroxisome proliferator-activated receptor (PPAR)α, which governs FA transport and β-oxidation, and the expression of Carnitine palmitoyltransferase (Cpt)-1α, cytochrome P450, family 4, subfamily a, polypeptide (Cyp4a)10, and Cyp4a14, which are key enzymes for hepatic fatty acids β-oxidation and ω-oxidation. Taken together, these results suggest that vitamin D deficiency is not a direct risk factor for hepatic lipid accumulation. Vitamin D deficiency alleviates acute alcohol-induced hepatic lipid accumulation through inhibiting hepatic de novo fatty acid syntheses and promoting fatty acid β-oxidation and ω-oxidation.     

Is plasma vitamin C an appropriate biomarker of vitamin C intake? A systematic review and meta-analysis

Background  

As the primary source of dietary vitamin C is fruit and to some extent vegetables, the plasma level of vitamin C has been considered a good surrogate or predictor of vitamin C intake by fruit and vegetable consumption. The purpose of this systematic review was to investigate the relationship between dietary vitamin C intakes measured by different dietary methods and plasma levels of vitamin C.