Analyzing vitamin D in foods and supplements: methodologic challenges

Dietary antioxidants and vascular calcification: From pharmacological mechanisms to challenges

Vascular calcification (VC), an actively regulated process, has been recognized as an independent and strong predictor of cardiovascular disease (CVD) and mortality worldwide. Diet has been shown to have a major role in the progression of VC. Oxidative stress (OS), a common pro-calcification factor, is closely related to VC, and evidence strongly suggests that dietary antioxidants directly prevent VC. Herein, we provided an overview of OS and its key role in VC and underlined the mechanisms of harmful effects of OS on VC. Furthermore, we introduced dietary antioxidants, and discussed about surrounding the challenges of dietary antioxidants in VC management. This review will benefit future research about the effects of dietary antioxidants on cardiovascular health.

An overview of food lipids toward food lipidomics

Increasing evidence regarding lipids' beneficial effects on human health has changed the common perception of consumers and dietary officials about the role(s) of food lipids in a healthy diet. However, lipids are a wide group of molecules with specific nutritional and bioactive properties. To understand their true nutritional and functional value, robust methods are needed for accurate identification and quantification. Specific analytical strategies are crucial to target specific classes, especially the ones present in trace amounts. Finding a unique and comprehensive methodology to cover the full lipidome of each foodstuff is still a challenge. This review presents an overview of the lipids nutritionally relevant in foods and new trends in food lipid analysis for each type/class of lipids. Food lipid classes are described following the LipidMaps classification, fatty acids, endocannabinoids, waxes, C8 compounds, glycerophospholipids, glycerolipids (i.e., glycolipids, betaine lipids, and triglycerides), sphingolipids, sterols, sercosterols (vitamin D), isoprenoids (i.e., carotenoids and retinoids (vitamin A)), quinones (i.e., coenzyme Q, vitamin K, and vitamin E), terpenes, oxidized lipids, and oxylipin are highlighted. The uniqueness of each food group: oil-, protein-, and starch-rich, as well as marine foods, fruits, and vegetables (water-rich) regarding its lipid composition, is included. The effect of cooking, food processing, and storage, in addition to the importance of lipidomics in food quality and authenticity, are also discussed. A critical review of challenges and future trends of the analytical approaches and computational methods in global food lipidomics as the basis to increase consumer awareness of the significant role of lipids in food quality and food security worldwide is presented.

Validation of Diet ID™ in Predicting Nutrient Intake Compared to Dietary Recalls, Skin Carotenoid Scores, and Plasma Carotenoids in University Students

Background and Aim: Collecting accurate dietary information in the research setting is challenging due to the inherent biases, duration, and resource-intensive nature of traditional data collection methods. Diet ID™ is a novel, rapid assessment method that uses an image-based algorithm to identify dietary patterns and estimate nutrient intake. The purpose of this analysis was to explore the criterion validity between Diet ID™ and additional measures of dietary intake. Methods: This prospective cohort study (n = 42) collected dietary information using Diet ID™, the Nutrition Data System for Research (NDSR), plasma carotenoid concentrations, and the Veggie Meter^® to estimate carotenoid levels in the skin. Results: There were significant correlations between Diet ID™ and NDSR for diet quality, calories, carbohydrates, protein, fiber, and cholesterol. Vitamin A and carotenoid intake were significantly correlated, with the exception of α-carotene and lycopene. Significant correlations were observed for calcium, folate, iron, sodium, potassium, Vitamins B₂, B₃, B₆, C, and E. Skin carotenoid scores and plasma carotenoids were correlated with carotenoid intake from Diet ID™. Conclusions: Diet ID™ may be a useful tool in nutrition research as a less time-intensive and minimally burdensome dietary data collection method for both participants and researchers.

Development of a two-dimensional liquid chromatography-tandem mass-spectrometry method for the determination of vitamin D2 in mushrooms

Different foods, especially mushrooms, are a valuable source of vitamin D2. However, published concentrations in mushrooms show large variabilities. One reason for this is certainly the high biological variability caused by growth conditions, and another could also be found in the analytical methodology. Therefore, this study aimed to develop a sensitive and highly selective two-dimensional liquid chromatography mass spectrometry (LC–MS/MS) method for vitamin D2 analysis in mushrooms. After validation, the method was applied to four different mushroom species. The developed method with a one-step extraction procedure showed a limit of detection of 0.01 µg vitamin D2/g dry mass (DM), a limit of quantification of 0.05 µg vitamin D2/g DM, and recovery rates between 87.6 and 94.8%. The total run time including the re-equilibration of the columns for the next injection was 7.5 min. After adding increased concentrations of pure substance to Pleurotus ostreatus, Lentinula edodes, and brown and white button mushrooms the standard addition plot showed excellent correlation coefficients (R²) of > 0.9994. Mean vitamin D2 concentrations were observed at 0.122 ± 0.007, 0.074 ± 0.005, 0.099 ± 0.007, and 0.073 ± 0.005 µg/g DM. The coefficient of variation (CV) was between 5.1 and 7.6%. This well-optimized, sensitive LC–MS/MS method, with a fast and simple sample preparation and a short run time, can be applied to future studies especially in different mushroom species with variable growing conditions. This will improve our knowledge about the vitamin D2 content in mushrooms.

Vitamin D composition of Australian foods

Australia needs accurate vitamin D food composition data to support public health initiatives. Previously, limitations in analytical methodology have precluded development of a comprehensive database. We used liquid chromatography with triple quadrupole mass spectrometry (LC-QQQ) to analyse 149 composite samples representing 98 foods (primary samples n = 896) in duplicate for vitamin D₃, 25-hydroxyvitamin D₃ (25(OH)D₃), vitamin D₂, 25(OH)D₂. The greatest concentrations of vitamin D₃ were found in canned salmon and a malted chocolate drink powder (fortified); chicken eggs and chicken leg meat contained the most 25(OH)D₃. Margarine (fortified) and chocolate contained the greatest concentrations of vitamin D₂, with smaller amounts found in various meat products. 25(OH)D₂ was detected in various foods, including meats, and was quantitated in lamb liver. These data advance knowledge of dietary vitamin D in Australia and highlight the importance of analysis of these four forms of vitamin D to accurately represent the vitamin D content of food.

An Approach to Investigate Content-Related Quality of Nutraceuticals Used by Slovenian Consumers: A Case Study with Folate and Vitamin D Supplements

A predisposition for the efficiency of nutraceuticals is that the product contains a sufficient quantity of a vitamin. Several studies have highlighted different quality issues. Our objective was to investigate whether the contents of the vitamins in selected types of food supplements were in accordance with labeling. We focused on two types of food supplements where content-related quality issues could result in public health risks: food supplements for supplementation with (a) folic acid (as 5-methyltetrahydrofolate (5-MTHF)) in pregnancy and (b) with vitamin D in the general population. The study was done on supplements from the global supply that are typically used by Slovenian consumers. We sampled one production batch of 30 different food supplements-six and 24 samples with 5-MTHF and cholecalciferol, respectively. We found samples with vitamin contents outside the 80-150% tolerance interval in both sets. Particularly, 5-MTHF was found to be more problematic, probably due to its lower stability. This study shows the need for better quality control. Quality control is needed during both the manufacturing process and product shelf lifetimes. Content quality should be also subject to external controls by authorities. Voluntarily quality control schemes would also enable consumers to identify products of sufficient quality.

The Moderate Correlation Between 25(OH)D Serum and Saliva in Healthy People with Low Vitamin D Intake

Purpose

The routine examination of vitamin D levels is carried out by checking serum 25(OH)D levels, while serum 1.25(OH)D levels are less frequently utilized. The proposition that testing for salivary vitamin D can show a correlation with serum levels in healthy people is questionable, especially with low vitamin D intake. This study aimed to find the correlation between vitamin D levels, which were assessed as 25(OH)D and 1.25(OH)D in saliva, and serum 25(OH)D and 1.25(OH)D levels in people with low vitamin D intake.

Patients and Methods

This study is a cross-sectional study involving healthy men and women, aged 18–60 years, carried out from August to November, 2020, in North Sumatra Province, Indonesia. The parameters studied were the 25(OH)D and 1.25(OH)D levels in saliva and serum, and vitamin D intake. The statistical analysis used was the Spearman correlation test, performed to determine the correlation between each parameter.

Results

This study involved 56 study subjects, who were rural adults (male or female) with a 78.6% deficiency in 25(OH)D found by examining saliva, and a 76.8% deficiency found by examining the serum. All of the subjects were categorized as having low vitamin D intake (less than 15 micrograms per day). The analysis showed a moderate correlation between levels of saliva 25(OH)D and serum 25(OH)D (p = 0.424), and a weak correlation between levels of saliva 1.25(OH)D and serum 25(OH)D (p = 0.339).

Conclusion

In people with low vitamin D intake, there was a moderate correlation between serum 25(OH)D and saliva, but a weak correlation was found in the 1.25(OH)D assay. The use of saliva 25(OH)D levels to detect 25(OH)D in the circulation is a possible non-invasive alternative to serum testing.

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Vitamin D analyses in veterinary feeds by gas chromatography-tandem mass spectrometry

This report examines the feasibility of determination of Vitamin D3, D2 and their 25-hydroxy metabolites utilizing Gas Chromatography Tandem Mass Spectrometry (GC/MS/MS) as a potential alternative to popular Liquid Chromatography Tandem Mass Spectrometric (LC/MS/MS) methodologies. The GC/MS/MS approach was found to operate reasonably well despite long-standing concerns that gas-liquid chromatography of vitamin D compounds invoke thermal rearrangements owing to the relatively high inlet and capillary column temperatures used. The workup procedure involved incubation of feed samples with concentrated potassium hydroxide for overnight fat saponification, extraction of D Vitamins in n-hexane and reaction with N,O-bis(trimethylsilyl)trifluoroacetamide at 70 °C for 30 mins. In addition to parent compounds, small amounts of pyro-, isopyro-, and iso-vitamin D and isotachysterol3 variants were obtained from each Vitamin D-related compound upon extraction and GC/MS/MS analysis. Mass spectral and chromatographic behavior of these compounds are herein described and interpreted. Multiple Reaction Monitoring settings on GC/MS/MS included m/z 456→351 for Vitamin D3 and m/z 486→363 for Vitamin D2. Trimethylsilylation enabled single predominant peaks for Vitamins D3 and D2, and sample workup in the presence of deuterated Vitamin D analogs enabled accurate and precise sensitivity to 1 ppb (ng/g) in feeds. The method could be extended with reasonable accuracy to 25-hydroxy (25OH) compounds, but accuracies would be significantly improved by inclusion of respective 25OH-specific deuterated internal standards. The method was applied to 27 submissions of suspect dog foods of which 22% were discovered elevated and 44% were discovered to contain toxic levels of Vitamin D3. The described method was thus discovered to provide a suitable mass spectrometric approach for Vitamin D, proving itself here specifically of value in detection of ergocalciferol and cholecalciferol in animal feeds. The specificity and sensitivity of the tandem quadrupole approach can enable suitable applicability to serum determination if desired.

Association of vitamin D status with liver and kidney disease: A systematic review of clinical trials, and cross-sectional and cohort studies

Abstract. Background: Vitamin D deficiency (VDD) is a major public health problem. There are few comprehensive systematic reviews about the relationship between Vitamin D status and liver and renal disease in Iran.

Methods: We systemically searched the following databases: Web of Science; PubMed; Cochrane Library; Scopus; Science Direct; Google Scholar and two Iranian databases (Scientific Information Database (SID) and IranMedex) up until November 2017 to identify all randomized control trials (RCTs), case control, cross-sectional and cohort studies investigating the association between vitamin D and any form of liver or kidney disease.

Results: Vitamin D insufficiency, or deficiency (VDD), is highly prevalent in Iran, reports varying between 44.4% in Isfahan to 98% in Gorgan. There is also a high prevalence of VDD among patients with liver or kidney disease, and the administration of vitamin D supplements may have beneficial effects on lipid profile, blood glucose, liver function and fatty liver disease, and bone health. Low serum vitamin D levels are related with abnormalities in these laboratory and clinical parameters.

Conclusion: VDD is prevalent in patients with chronic liver or renal disease in Iran. There appear to be several beneficial effects of vitamin D supplementation in vitamin D deficient patients with liver or kidney disease.

Vitamin D3 content of cows' milk produced in Northern Ireland and its efficacy as a vehicle for vitamin D fortification: a UK model

Cows' milk is a relatively poor source of vitamin D but figures listed in UK food composition tables may be outdated. Samples of milk were collected for 1-year and vitamin D₃ concentrations analysed using HPLC. Milk consumption data were obtained from the National Diet and Nutrition Survey (Years 1-4). A theoretical model applied vitamin D₃ fortifications of 1 μg, 1.5 μg and 2 μg/100g to simulate improvements in vitamin D intakes. Mean ± SD vitamin D₃ in whole milk was 0.06 ± 0.02 μg/100g. No seasonal differences were apparent. Fortification of cows' milks with 1 μg, 1.5 μg and 2.0 μg/100g, theoretically increased median vitamin D intakes from 2.0 μg/day to 4.2 μg, 5.1 μg and 5.9 μg/day, respectively. Higher vitamin D₃ in milk from this study than that currently in food composition tables, suggests further analysis is warranted. This model suggests vitamin D fortification of cows' milk is an effective strategy to help more of the population achieve recently revised RNIs for vitamin D.

The measurement of vitamin D metabolites part II-the measurement of the various vitamin D metabolites

Today, the possibility exists to measure a number of different vitamin D metabolites with accurate and precise methods. The most abundant vitamin D metabolite, 25(OH)D, is considered the best marker for estimating vitamin D status and is therefore the most commonly measured in clinical practice. There is no consensus on the added value of measuring other metabolites beyond 25-hydroxyvitamin D, although, in some special clinical scenarios and complicated cases, these metabolites may provide just the information needed for an accurate diagnosis. The problem this review addresses is which metabolite to measure and when and how to measure it.

Vitamin D Deficiency and Autism Spectrum Disorder

Vitamin D is a neurosteroid hormone crucially involved in neurodevelopment. Neural cell proliferation, neurotransmission, oxidative stress and immune function represent the main mechanisms mediated by vitamin D in the Central Nervous System. Therefore, its deficiency during pregnancy and early childhood may significantly impact on a developing brain, leading to possible adverse neuropsychological outcomes including Autism Spectrum Disorder (ASD). Significant vitamin D deficiency is described within children affected by ASD and in pregnant mothers whose offspring will later develop ASD, suggesting a possible role of the hormone as a contributing risk factor in the etiopathogenesis of ASD. We reviewed the actual literature on the potential contributing role of prenatal and early postnatal vitamin D deficiency in ASD etiopathogenesis, at both genetic and environmental levels, and the possible effect of vitamin D supplementation in autistic children. Conflicting but promising results emerged on the topic. Further Randomized Controlled Trials studies carried out during pregnancy and early infancy are necessary for better understanding the possible contribution of vitamin D deficiency in the etiopathogenesis of autism and the potential efficacy of the hormone supplementation in the improvement of ASD core symptoms.

Specialized food composition dataset for vitamin D content in foods based on European standards: Application to dietary intake assessment

A review of national nutrition surveys from 2000 to date, demonstrated high prevalence of vitamin D intakes below the EFSA Adequate Intake (AI) (<15μg/d vitamin D) in adults across Europe. Dietary assessment and modelling are required to monitor efficacy and safety of ongoing strategic vitamin D fortification. To support these studies, a specialized vitamin D food composition dataset, based on EuroFIR standards, was compiled. The FoodEXplorer™ tool was used to retrieve well documented analytical data for vitamin D and arrange the data into two datasets - European (8 European countries, 981 data values) and US (1836 data values). Data were classified, using the LanguaL™, FoodEX2 and ODIN classification systems and ranked according to quality criteria. Significant differences in the content, quality of data values, missing data on vitamin D₂ and 25(OH)D₃ and documentation of analytical methods were observed. The dataset is available through the EuroFIR platform.

Compliance with Dietary Guidelines and Increased Fortification Can Double Vitamin D Intake: A Simulation Study

OBJECTIVE

The study aimed to determine the potential of compliance with Food-Based Dietary Guidelines (FBDG) and increased vitamin D fortification to meet the recommended intake level of vitamin D at 10 µg/day based on minimal exposure to sunlight.

METHODS

The main dietary sources of vitamin D were derived from national dietary surveys in adults from United Kingdom (UK) (n = 911), Netherlands (NL) (n = 1,526), and Sweden (SE) (n = 974). The theoretical increase in population vitamin D intake was simulated for the following: (1) compliance with FBDG, (2) increased level of vitamin D in commonly fortified foods, and (3) combination of both.

RESULTS

Median usual vitamin D intake was 2.4 (interquartile range 1.7-3.4) µg/day in UK, 3.4 (2.7-4.2) µg/day in NL, and 5.3 (3.9-7.3) µg/day in SE. The top 3 dietary sources of vitamin D were fish, fat-based spreads (margarines), and meat. Together, these delivered up to two-thirds of total vitamin D intake on average. Compliance with FBDG for fish, margarine, and meat increased vitamin D intake to 4.6 (4.1-5.1) µg/day in UK, 5.2 (4.9-5.5) µg/day in NL, and 7.7 (7.0-8.5) µg/day in SE. Doubling the vitamin D levels in margarines and milk would increase vitamin D intake to 4.9 (3.6-6.5) µg/day in UK, 6.6 (4.8-8.6) µg/day in NL, and 7.2 (5.2-9.8) µg/day in SE. Combining both scenarios would increase vitamin D intake to 7.9 (6.8-9.2) µg/day in UK, 8.8 (7.4-10.4) µg/day in NL, and 8.9 (6.9-11.8) µg/day in SE.

CONCLUSION

This study highlights the potential of dietary measures to double the current vitamin D intake in adults.

Vitamin D concentrations in fortified foods and dietary supplements intended for infants: Implications for vitamin D intake

Due to potential overages to cover losses during shelf life, the actual vitamin D concentration of fortified foods and dietary supplements may deviate from the label. In this pilot study the vitamin D concentrations of fortified foods (n=29; follow-on formula, baby porridge, curd cheese dessert) and dietary supplements (n=15), both specifically intended for infants, were analytically determined. Compared to the declared values, the vitamin D content ranged from 50% to 153% for fortified foods and from 8% to 177% for supplements. In general, both instant follow-on formula and oil-based supplements had a measured vitamin D content similar to or higher than the labelled value. Ready-to-eat baby porridge was the only category in which all measured vitamin D concentrations were below the declared value (74-81%). The use of label information for fortified foods and dietary supplements may result in invalid estimations of vitamin D intake distributions of infants; both under- and overestimation may occur.

Calcium to phosphorus ratio, essential elements and vitamin D content of infant foods in the UK: Possible implications for bone health

Adequate intake of calcium and phosphorus in the appropriate ratio of 1-2:1 (Ca:P), in addition to magnesium and vitamin D, is vital for bone health and development of infants. In this feasibility study, the ratio of Ca:P in conjunction with vitamin D and other essential elements (Cu, Fe, K, Mg, Na, and Zn) in a range of commercial infant food products in the UK was investigated. The elemental analysis was carried out using inductively coupled plasma optical emission spectrometry, and vitamin D levels were determined using an enzyme-linked immunosorbent assay. The quantitative data were further evaluated, based on a standardised menu, to measure the total daily intake of an infant aged 7-12 months against the Reference Nutrient Intake. The results from the study show that the Ca:P ratio of the infant's total dietary intake was within the recommended range at 1.49:1. However, the level of intake for each of the nutrients analyzed, with the exception of sodium, was found to be above the Reference Nutrient Intake, which warrants further investigation in relation to both micronutrient interactions and in situations where the intake of fortified infant formula milk is compromised. Finally, as the study is the first to include consumption of infant snack products, the level of total calorie intake was also calculated in order to assess the total daily estimated energy intake; the results indicate that energy intakes exceed recommendations by 42%, which may have implications for obesity.

A rapid method for the separation of vitamin D and its metabolites by ultra-high performance supercritical fluid chromatography-mass spectrometry

In this study, a new supercritical fluid chromatography-mass spectrometry (SFC-MS) method has been developed for the separation of nine vitamin D metabolites within less than eight minutes. This is the first study of analysis of vitamin D and its metabolites carried out by SFC-MS. Six columns of orthogonal selectivity were examined, and the best separation was obtained by using a 1-aminoanthracene (1-AA) column. The number and the position of hydroxyl groups in the structure of the studied compounds as well as the number of unsaturated bonds determine the physiochemical properties and, thus the separation of vitamin D metabolites that is achieved on this column. All D2 and the D3 forms were baseline separated with resolution values>1.5. The effects of pressure, temperature, flow rate and different gradient modes were studied. Electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) were compared in positive mode, both by direct infusion and after SFC separation. The results showed that the sensitivity in APCI(+) was higher than in ESI(+) using direct infusion. In contrast, the sensitivity in APCI(+) was 6-fold lower than in ESI(+) after SFC separation. The SFC-MS method was validated between 10 and 500ng/mL for all analytes with coefficient of determination (R(2))≥0.999 for all calibration curves. The limits of detection (LOD) were found to range between 0.39 and 5.98ng/mL for 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) and 1-hydroxyvitamin D2 (1OHD2), respectively. To show its potential, the method was applied to human plasma samples from healthy individuals. Vitamin D3 (D3), 25-hydroxyvitamin D3 (25OHD3) and 24,25(OH)2D3 were determined in plasma samples and the concentrations were 6.6±3.0ng/mL, 23.8±9.2ng/mL and 5.4±2.7ng/mL, respectively.

Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior

Serotonin regulates a wide variety of brain functions and behaviors. Here, we synthesize previous findings that serotonin regulates executive function, sensory gating, and social behavior and that attention deficit hyperactivity disorder, bipolar disorder, schizophrenia, and impulsive behavior all share in common defects in these functions. It has remained unclear why supplementation with omega-3 fatty acids and vitamin D improve cognitive function and behavior in these brain disorders. Here, we propose mechanisms by which serotonin synthesis, release, and function in the brain are modulated by vitamin D and the 2 marine omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Brain serotonin is synthesized from tryptophan by tryptophan hydroxylase 2, which is transcriptionally activated by vitamin D hormone. Inadequate levels of vitamin D (∼70% of the population) and omega-3 fatty acids are common, suggesting that brain serotonin synthesis is not optimal. We propose mechanisms by which EPA increases serotonin release from presynaptic neurons by reducing E2 series prostaglandins and DHA influences serotonin receptor action by increasing cell membrane fluidity in postsynaptic neurons. We propose a model whereby insufficient levels of vitamin D, EPA, or DHA, in combination with genetic factors and at key periods during development, would lead to dysfunctional serotonin activation and function and may be one underlying mechanism that contributes to neuropsychiatric disorders and depression. This model suggests that optimizing vitamin D and marine omega-3 fatty acid intake may help prevent and modulate the severity of brain dysfunction.

Fortification of foods with vitamin D in India

Vitamin D deficiency is widely prevalent in India, despite abundant sunshine. Fortification of staple foods with vitamin D is a viable strategy to target an entire population. Vitamin D fortification programs implemented in the United States and Canada have improved the vitamin D status in these countries, but a significant proportion of the population is still vitamin D deficient. Before fortification programs are designed and implemented in India, it is necessary to study the efficacy of the American and Canadian vitamin D fortification programs and then improve upon them to suit the Indian scenario. This review explores potential strategies that could be used for the fortification of foods in the Indian context. These strategies have been proposed considering the diverse dietary practices necessitated by social, economic, cultural and religious practices and the diverse climatic conditions in India. Fortification of staple foods, such as chapati flour, maida, rice flour and rice, may be more viable strategies. Targeted fortification strategies to meet the special nutritional needs of children in India are discussed separately in a review entitled, "Fortification of foods with vitamin D in India: Strategies targeted at children".

Vitamin D intakes of adults differ by income, gender and race/ethnicity in the U.S.A., 2007 to 2010

OBJECTIVE

To determine if dietary, supplemental and total vitamin D intakes in the USA are influenced by income, race/ethnicity or gender.

DESIGN

Cross-sectional. US vitamin D intakes were estimated by poverty income ratio (PIR), race/ethnicity and gender using 24 h dietary intake recalls and dietary supplement use questionnaires. Statistical analyses of weighted data were performed using SAS (version 9.2) to estimate means and their standard errors. Race and ethnic intake differences controlling for PIR, gender and age were assessed by ANCOVA.

SUBJECTS

Adults aged ≥19 years.

SETTING

The 2007-2010 National Health and Nutrition Examination Survey, USA.

RESULTS

Total (dietary and supplement) vitamin D intake was greater in the high (10.0 (se 0.30) μg/d) v. the medium (7.9 (se 0.3) μg/d) or the low (8.0 (se 0.3) μg/d) PIR categories. Total vitamin D intake of non-Hispanic Whites (10.6 (se 0.4) μg/d) was greater than that of Hispanics (8.1 (se 0.3) μg/d) and non-Hispanic Blacks (7.1 (se 0.3) μg/d). Supplemental vitamin D intake was greater by females (5.3 (se 0.2) μg/d) than by males (3.3 (se 0.2) μg/d). Participants with high income were more likely to be vitamin D supplement users (33.0%) than those with medium (22.5%) or low (17.6%) income. High-income non-Hispanic Whites had the lowest percentage (57%) not meeting the Estimated Average Requirement for vitamin D. Fortified milk and milk products provided 43.7% of the dietary vitamin D intake.

CONCLUSIONS

Public health efforts should expand the number of vitamin D-fortified foods and encourage the consumption of foods high in vitamin D and use of supplements.

Vitamin D hormone regulates serotonin synthesis. Part 1: relevance for autism

Serotonin and vitamin D have been proposed to play a role in autism; however, no causal mechanism has been established. Here, we present evidence that vitamin D hormone (calcitriol) activates the transcription of the serotonin-synthesizing gene tryptophan hydroxylase 2 (TPH2) in the brain at a vitamin D response element (VDRE) and represses the transcription of TPH1 in tissues outside the blood-brain barrier at a distinct VDRE. The proposed mechanism explains 4 major characteristics associated with autism: the low concentrations of serotonin in the brain and its elevated concentrations in tissues outside the blood-brain barrier; the low concentrations of the vitamin D hormone precursor 25-hydroxyvitamin D [25(OH)D3]; the high male prevalence of autism; and the presence of maternal antibodies against fetal brain tissue. Two peptide hormones, oxytocin and vasopressin, are also associated with autism and genes encoding the oxytocin-neurophysin I preproprotein, the oxytocin receptor, and the arginine vasopressin receptor contain VDREs for activation. Supplementation with vitamin D and tryptophan is a practical and affordable solution to help prevent autism and possibly ameliorate some symptoms of the disorder.

Vitamin D3 effects on lipids differ in statin and non-statin-treated humans: superiority of free 25-OH D levels in detecting relationships

CONTEXT

Inverse associations between 25-OH vitamin D levels and cardiovascular morbidity and mortality have been reported.

OBJECTIVES

Our goals were to 1) investigate effects of correcting inadequate D status on lipids, 2) determine whether free 25-OH D is better correlated with lipids than total 25-OH D.

DESIGN

A randomized, double-blind placebo-controlled trial was performed.

SETTING

Participants resided in the general community.

PARTICIPANTS

Adults with inadequate D status were randomized to D3: 14 men, 12 women, age 60 ± 8 years (mean ± SD) or placebo: 12 men, 11 women: 59 ±12 years.

INTERVENTION

Responses to 12-week oral vitamin D3 titrated (1000-3000 IU/d) to achieve 25-OH D levels ≥25 ng/mL were compared to placebo.

MAIN OUTCOME MEASURES

Measurements were 25-OH D (tandem mass spectometry), free 25-OH D (direct immunoassay), lipids (directly measured triglyceride, cholesterol, and subfractions; plant sterols and cholesterol synthesis precursors), and safety labs before and after 6 and 12 weeks D3 or placebo. Data were analyzed by repeated measures ANOVA and linear regression.

RESULTS

Vitamin D3 was titrated to 1000 IU/d in 15/26 (58%), to 2000 IU/d in 10, and 3000 IU/d in one patient. D3 had no effect on cholesterol or cholesterol subfractions except for trends for decreases in atorvastatin-treated patients (cholesterol, P = .08; low-density lipoprotein [LDL] cholesterol, P = .05). Decreased campesterol concentrations (P = .05) were seen with D3 but not placebo in statin-treated patients. Relationships between total 25-OH D and lipids were not detected, but inverse linear relationships were detected between free 25-OH D and triglycerides (P = .03 for all participants [n = 49], P = .03 in all statin-treated [n = 19], and P = .0009 in atorvastatin-treated [n = 11]), and between free 25-OH D and LDL cholesterol (P = .08 overall, P = .02 in all statin-treated, and P = .03 for atorvastatin-treated), and total cholesterol (P = .09 overall; P = .04 for all statin-treated, and P = .05 for atorvastatin-treated).

CONCLUSIONS

Vitamin D lipid-lowering effects appear limited to statin-treated patients and are likely due to decreased cholesterol absorption. Relationships between lipids and D metabolites were only detected when free 25-OH D was measured, suggesting the superiority of determining free 25-OH D levels compared to total 25-OH vitamin D levels when analyzing biologic responses.

The role of mass spectrometry in the analysis of vitamin D compounds

This review highlights the superseding role of mass spectrometry in the structural characterization and quantitation of vitamin D compounds in comparison to other analytical methods (e.g., UV, bioassays) that lack the sensitivity and specificity of mass spectrometry. After a short introduction to the biochemistry of vitamin D compounds, an overview of the current techniques to characterize and quantitate vitamin D compounds is given with emphasis on the contribution of mass spectrometry.

Serum levels of 3-epi-25-OH-D3 during hypervitaminosis D in clinical practice

CONTEXT

Intoxication from vitamin D supplements has been rarely reported, but nowadays, it occurs more frequently. The presence of the C-3 epimer of 25-hydroxyvitamin D(3) (3-epi-25-OH-D(3)) is highly prevalent in adults, although there is little information regarding its in vivo relevance, if any, especially under pathological conditions.

OBJECTIVE

Our aim was to assess the presence of the 3-epi-25-OH-D(3) in serum samples displaying 25-OH-D(3) concentrations indicative of hypervitaminosis D.

DESIGN, SETTING, PATIENTS, AND MAIN OUTCOME MEASURE

A total of 58 samples displaying a wide range of concentrations of 25-OH-D(3) (>64-439 ng/ml) by ultrafast liquid chromatography were consecutively recruited and reassessed for the presence of 3-epi-25-OH-D(3) using a second chromatographic system. Data from additional biochemical tests performed as part of the patient evaluation were also recorded.

RESULTS

Mean relative contribution of 3-epi-25-OH-D(3) was less than 4%, and concentrations ranged from 2-28.6 ng/ml. Serum levels of the C3 epimer, but not the relative contribution, correlate with serum 25-OH-D(3). Overall, in subjects with 25-OH-D(3) concentrations indicative of hypervitaminosis D, the presence of the C-3 epimer and its levels were apparently unrelated to age, serum markers of renal and liver function, acute-phase reactants, and the presence of hypercalcemia. 3-Epi-25-OH-D(3) did not correlate with PTH, but subjects displaying PTH suppression (<14 pg/ml) showed higher concentrations of 3-epi-25-OH-D(3).

CONCLUSION

The relative contribution of 3-epi-25-D(3) was not significantly altered during hypervitaminosis D, although the absolute levels reached in serum may be biologically relevant. From a clinical viewpoint, although the small size of the group may affect the lack of relationships, the presence of 3-epi-25-OH-D(3) was apparently unrelated to serum markers of renal and liver function, acute-phase reactants, PTH, and the presence of hypercalcemia.

The impact of vitamin D on pregnancy: a systematic review

Hypovitaminosis D is common in pregnancy. To systematically review the evidence on vitamin D-dependent pregnancy outcomes, PubMed and Embase were searched for randomized control trials, cohort and case-control studies. In randomized control trials (n = 7), larger doses of vitamin D resulted in higher 25-hydroxylated vitamin D (25OHD) levels (n = 6), increased maternal weight gain (n = 1), and fewer classical vitamin D deficiency symptoms (n = 1). In observational studies (n = 32), lower vitamin D intake, or low 25OHD-levels, were associated with adverse fertility parameters (n = 2), preeclampsia (n = 5), gestational diabetes or higher blood glucose (n = 6), bacterial vaginosis (n = 4), primary cesarean section (n = 1), none (n = 3) or a few days' (n = 2) shorter gestation, and postpartum depression (n = 1). Studies with few participants having low 25OHD did not identify an association to preeclampsia (n = 5) or gestational diabetes (n = 2). Increased odds of pregnancy-associated breast cancer with 25OHD >25.8 nmol/L were observed (n = 1). In conclusion, an effect of vitamin D on several pregnancy outcomes is suggested.

Genetic and environmental predictors of serum 25-hydroxyvitamin D concentrations among middle-aged and elderly Chinese in Singapore

Vitamin D is known for maintaining Ca homeostasis and bone structure, and may also decrease susceptibility to chronic and infectious diseases. However, data on vitamin D status and its predictors among Southeast Asian populations are limited. We evaluated the distribution and determinants (genetic and environmental) of serum 25-hydroxyvitamin D (25(OH)D) concentrations among 504 middle-aged and elderly participants (aged 45-74 years) in the Singapore Chinese Health Study. Data on dietary and other lifestyle factors were collected by trained interviewers. Serum 25(OH)D concentrations and genetic polymorphisms in vitamin D metabolism pathway enzymes (cytochrome P450 (CYP) 2R1, 3A4, 27B1, 24A1; vitamin D binding protein (also known as group-specific component, GC); and vitamin D receptor) were measured using stored biospecimens. Mean 25(OH)D concentration was 68·8 nmol/l. Serum 25(OH)D concentrations were positively associated with dietary vitamin D intake, and inversely associated with hours spent sitting at work. BMI was not associated with 25(OH)D concentrations. CYP2R1 rs10741657, rs12794714, rs1993116; CYP3A4 rs2242480; and GC rs4588, rs7041, rs16847015, rs2298849 were statistically significantly associated with 25(OH)D concentrations. Individuals with the Gc2-2 haplotype (rs4588AA/rs7041TT) had statistically significantly lower 25(OH)D concentrations compared to all other Gc haplotypes (P-trend < 0·001). The majority of participants (86 %) had 25(OH)D concentrations ≥ 50 nmol/l, which is consistent with the 2011 Institute of Medicine (US) recommendation for bone health, and 32 % had concentrations of ≥ 75 nmol/l that are thought to be required for broader health effects. Dietary vitamin D intake, hours spent indoors at work and genetic variation in CYP2R1, CYP3A4 and GC are significant predictors of 25(OH)D concentrations among Singapore Chinese.

Vitamin D intake from food and supplements among Ontario women based on the US block food frequency questionnaire with and without modification for Canadian food values

OBJECTIVES

To measure and compare dietary vitamin D intake among women in Ontario using a modified Block 1998 (US) food frequency questionnaire (FFQ) before and after modification for Canadian-specific vitamin D food fortification.

METHODS

An age-stratified random sample of 3,471 women in Ontario (aged 25-74) was identified using random digit dialing methods. Standard US food values and a modified Canadian-specific vitamin D nutrient analysis were applied to the FFQ.

RESULTS

Intake of vitamin D from foods (Canadian nutrient analysis) was 5.3 +/- 3.4 microg/day (mean +/- SD) and 45% of women reported vitamin D intake from supplements. Total vitamin D intakes met the current Adequate Intakes of 5, 10 and 15 microg/day for only 62%, 47%, and 28% of women aged < or = 50, 51-70 and > or = 71, respectively. Relatively high agreement was found between the US and Canadian nutrient analysis methods of measuring vitamin D from food (weighted kappa = 0.74, 95% CI 0.72-0.76). Intake differences (US minus Canadian) ranged from -5.0 microg/day to +2.0 microg/day (1st-99th percentile); however, the mean difference was only -0.54 microg/day (95% CI: -0.58 to -0.50).

CONCLUSIONS

Lower than recommended total vitamin D intakes were observed among our study participants which may negatively impact the health status of women. Adjustment for Canadian food fortification and the inclusion of fatty fish had little impact on the measurement of vitamin D from food.

Development and optimization of an LC-MS/MS-based method for simultaneous quantification of vitamin D2 , vitamin D3 , 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3

Simultaneous and accurate measurement of vitamin D and 25-hydroxyvitamin D in biological samples is a barrier limiting our ability to define "optimal" vitamin D status. Thus, our goal was to optimize conditions and evaluate an LC-MS method for simultaneous detection and quantification of vitamin D(2) , vitamin D(3) , 25-hydroxyvitamin D(2) and 25-hydroxyvitamin D(3) in serum. Extraction and separation of vitamin D forms were achieved using acetone liquid-liquid extraction and by a reversed phase C8 column, respectively. Detection was performed on a triple quadrupole tandem mass spectrometer (QQQ-MS/MS) equipped with atmospheric pressure photo ionization source. The LOQs for all analytes tested were 1 ng/mL for hydroxylated molecules and 2 ng/mL for the parent vitamin Ds. RSD at lower LOQ (2 ng/mL) and in medium (80 ng/mL) and high (200 ng/mL) quality control samples did not exceed 20 and 15% CV, respectively. Accuracy of the method for determination of hydroxylated molecules was also validated using National Institutes of Standards and Technology standard samples and found to be in the range of 90.9-111.2%. In summary, a sensitive and reproducible method is reported for simultaneous quantification of vitamin D(2) , vitamin D(3) , 25-hydroxyvitamin D(2) and 25-hydroxyvitamin D(3) molecules in biological samples.

Advantages of dietary, exercise-related, and therapeutic interventions to prevent and treat sarcopenia in adult patients: an update

Sarcopenia is the loss of skeletal muscle mass and function with aging. Although the term sarcopenia was first coined in 1989, its etiology is still poorly understood. Moreover, a consensus for defining sarcopenia continues to elude us. Sarcopenic changes in the muscle include losses in muscle fiber quantity and quality, alpha-motor neurons, protein synthesis rates, and anabolic and sex hormone production. Other factors include basal metabolic rate, increased protein dietary requirements, and chronic inflammation secondary to age-related changes in cytokines and oxidative stress. These changes lead to decreased overall physical functioning, increased frailty, falls risk, and ultimately the loss of independent living. Because the intertwining relationships of these factors are complex, effective treatment options are still under investigation. The published data on sarcopenia are vast, and this review is not intended to be exhaustive. The aim of this review is to provide an update on the current knowledge of the definition, etiology, consequences, and current clinical trials that may help address this pressing public health problem for our aging populations.

Comparison of analysis of vitamin D3 in foods using ultraviolet and mass spectrometric detection

A method for analysis of vitamin D(3) in commonly fortified foods and in fish, which contains endogenous vitamin D(3), was developed by combining the best aspects of two official methods. The ethyl ether/petroleum ether extraction procedure from AOAC 992.26 was combined with the chromatographic separation and use of an internal standard (vitamin D(2)) from AOAC 2002.05 to produce a method that was applicable to a variety of food samples. Results for skim milk, orange juice, breakfast cereal, salmon, a diluted USP reference standard (vitamin D(3) in peanut oil), and processed cheese are presented. Results indicated that UV detection was adequate in most cases, but the absence of interfering species must be determined in each food by mass spectrometry. Selected ion monitoring (SIM) atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) was shown to produce statistically indistinguishable results compared to UV detection for the skim milk, orange juice, multigrain cereal, and salmon samples. The processed cheese exhibited interferences that precluded quantification of vitamin D(3) by UV detection, and therefore, only SIM APCI-MS data for that sample were valid.

Assessing vitamin D contents in foods and supplements: challenges and needs

Scientists need specific data on the amounts of vitamin D in foods and dietary supplements to facilitate the assessment of vitamin D dietary intake. This vitamin is available in foods both naturally and from fortification. The Nutrient Data Laboratory of the US Department of Agriculture (USDA) is collaborating with vitamin D experts to review and develop methods for analyzing the vitamin D content of foods and to use these methods to analyze the vitamin D content of certain foods and dietary supplements. In this article, we review existing sources of vitamin D data on foods and dietary supplements, describe the USDA's Dietary Supplements Ingredients Database, and discuss the development of the USDA's vitamin D database for foods. In addition, we define the challenges and needs related to providing updated data on the vitamin D content of foods and supplements. After we analyze the vitamin D content of these food samples, we will disseminate the current values in the National Nutrient Database for Standard Reference (Internet: http://www.ars.usda.gov/nutrientdata).

Assessing the vitamin D status of the US population

This article describes the information currently available in the National Nutrition Monitoring System that is relevant to assessing the vitamin D status of US population groups, the strengths and limitations of this information, and selected results of vitamin D nutritional status assessments. The National Health and Nutrition Examination Survey (NHANES) provides information on vitamin D intakes only from 1988 to 1994. NHANES collected information on supplement use and circulating 25-hydroxyvitamin D [25(OH)D] concentrations from 1988 through current surveys. The National Nutrient Database for Standard Reference started providing limited data on the vitamin D content of foods in 2002 and continues to update these values. The Food Label and Package Survey provides 2006-2007 label information on vitamin D fortification of marketed foods. Despite limitations in the available data and controversies about appropriate criteria for evaluating vitamin D status among population groups, we can make some useful comparisons of vitamin D status among life-stage groups. In general, males have higher vitamin D intakes and 25(OH)D concentrations than do females. Children tend to have higher vitamin D status than adults. The increasing use of multivitamin-mineral dietary supplements in younger to older adults is not associated with a corresponding increase in serum 25(OH)D concentrations. In general, leaner individuals have higher circulating concentrations of 25(OH)D and supplement use than do heavier individuals. Finally, non-Hispanic whites tend to have higher vitamin D status than do non-Hispanic blacks and Mexican Americans.