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Advancements in Nutritional Strategies for Gestational Diabetes Management: A Systematic Review of Recent Evidence.
Sánchez-García, JC, Saraceno López-Palop, I, Piqueras-Sola, B, Cortés-Martín, J, Mellado-García, E, Muñóz Sánchez, I, Rodríguez-Blanque, R
Journal of clinical medicine. 2023;13(1)
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Gestational Diabetes Mellitus (GDM) causes hyperglycaemia due to the deficit of insulin during pregnancy. Dietary and lifestyle management plays a vital role in maintaining glycaemic control in women with GDM to avoid health risks to the mother and baby. Therefore, this systematic review of fourteen randomised controlled trials evaluated the latest research advancements to identify effective nutritional strategies for managing hyperglycaemia in women with GDM. Among all the dietary strategies implemented in the included randomised controlled trials, probiotic supplementation and supplementation of probiotics and vitamin D were most effective in GDM. Further robust studies are required to evaluate the potential effectiveness of different nutritional strategies for managing GDM. Healthcare professionals can use the results of this systematic review to understand the latest evidence supporting nutritional strategy for women with GDM and the need for personalised support for managing hyperglycaemia in GDM.
Abstract
Gestational diabetes mellitus (GDM) is defined as hyperglycaemia first detected at any time during pregnancy with values lower than those determined by the WHO for diabetes diagnosis in adults. This pathology, with a worldwide prevalence of 13.4%, causes significant maternal and foetal risks. The first line of treatment consists of maintaining normo-glycaemia through an adequate diet and lifestyle changes. The aim is to synthesize the scientific evidence updating the nutritional recommendations for the effective management of GDM. A systematic review of the scientific literature was conducted following the PRISMA guidelines. Randomized clinical trials published within the last five years and providing information on nutritional recommendations to achieve an effective management of gestational diabetes were selected. The databases searched were PubMed, the WOS Core Collection, SCOPUS, and CINAHL, using the MeSH terms: "Diabetes, Gestational"; "Nutrition Assessment (nutrition*)"; "Diet"; "Eating"; and "Food"; with the Boolean operators "AND" and "OR". The PEDro scale (Physiotherapy Evidence Database) was used to assess the scientific quality of the studies, with a mean score of 8.9, indicating an average good scientific quality. Results: A total of 809 papers were collected, of which, after applying the inclusion and exclusion criteria, 14 randomized clinical trials were selected. Probiotic supplementation and co-supplementation with vitamin D have been found to be the most beneficial options for both mothers with GDM and neonates, but the most effective regimens are not known. Diets enriched with extra virgin olive oil (EVOO) and oat bran, as well as some recommendations focused on carbohydrates also seem effective, as well as diets designed for this group of women with GDM such as "CHOICE". Conclusions: Although there are numerous proposals that have been published in recent years focused on the diet of women with GDM in order to improve their results and those of their children, it is the supplementation with probiotics and the co-supplementation with vitamin D that is most agreed upon as beneficial; however, more research is needed into which protocols are most effective. Other proposals that could also be beneficial should be further studied.
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Association of Vitamin D Level and Maternal Gut Microbiome during Pregnancy: Findings from a Randomized Controlled Trial of Antenatal Vitamin D Supplementation.
Aparicio, A, Gold, DR, Weiss, ST, Litonjua, AA, Lee-Sarwar, K, Liu, YY
Nutrients. 2023;15(9)
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Changes in the gut bacteria during pregnancy and a lack of vitamin D can have negative health consequences for both mother and child. Vitamin D has important functions in the human body and is key in regulating immune and inflammatory responses. Evidence suggests that vitamin D helps to maintain gut wall integrity and regulate inflammatory mechanisms in response to bacteria. Gut bacteria themselves have immune regulatory functions, and unfavourable disruptions in the composition of the bacteria are associated with chronic inflammatory diseases. Evidence shows gut bacteria composition is influenced by Vitamin D. During pregnancy, a substantial alteration in gut bacteria composition occurs and as pregnancy advances, there's typically an increase in bacteria linked to inflammation. This study analysed the data from the Vitamin D Antenatal Asthma Reduction Trial (VDAART, 2014), a randomised placebo controlled trial which gathered information on the impact of vitamin D on various markers as well as gut microbiome composition in pregnant women. For the study all participants took a daily multivitamin with 400 IU Vitamin D during the third trimester of pregnancy, and were given either an additional 4000IU of Vitamin D or a placebo. Results were drawn from 114 participants and their baseline vitamin D levels in early pregnancy, its changes over the trial period, as well as gut bacteria composition. The vitamin D levels at the start aligned with expected outcomes and was strongly linked to race, income, and education level. The baseline vitamin D level in early pregnancy also showed a connection to certain gut microbiome composition. However, these bacterial constellations remained robust and did not show any changes in response to Vitamin D supplementation throughout pregnancy. During the trial, most participant's vitamin D levels increased, especially those in the 4400 IU treatment group. Interestingly, women whose vitamin D levels did not increase much throughout the trial displayed a higher abundance of a bacteria called Desulfovibrio. Desulfovibrio is associated with an increased incidence of respiratory and inflammatory bowel diseases and the authors suggested that increasing vitamin D during pregnancy might help prevent the growth of more unfavourable bacteria like Desulfovibrio. Further long-term research is needed to confirm this idea.
Abstract
Shifts in the maternal gut microbiome and vitamin D deficiency during pregnancy have been associated, separately, with health problems for both the mother and the child. Yet, they have rarely been studied simultaneously. Here, we analyzed the gut microbiome (from stool samples obtained in late pregnancy) and vitamin D level (from blood samples obtained both in early and late pregnancy) data of pregnant women in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a randomized controlled trial of vitamin D supplementation during pregnancy, to investigate the association of vitamin D status on the pregnant women's microbiome. To find associations, we ran linear regressions on alpha diversity measures, PERMANOVA tests on beta diversity distances, and used the ANCOM-BC and Maaslin2 algorithms to find differentially abundant taxa. Analyses were deemed significant using a cut-off p-value of 0.05. We found that gut microbiome composition is associated with the vitamin D level in early pregnancy (baseline), the maternal gut microbiome does not show a shift in response to vitamin D supplementation during pregnancy, and that the genus Desulfovibrio is enriched in women without a substantial increase in vitamin D level between the first and the third trimesters of pregnancy. We conclude that increasing the vitamin D level during pregnancy could be protective against the growth of sulfate-reducing bacteria such as Desulfovibrio, which has been associated with chronic intestinal inflammatory disorders. More in-depth investigations are needed to confirm this hypothesis.
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Effect of an Immune-Boosting, Antioxidant and Anti-Inflammatory Food Supplement in Hospitalized COVID-19 Patients: A Prospective Randomized Pilot Study.
Reino-Gelardo, S, Palop-Cervera, M, Aparisi-Valero, N, Espinosa-San Miguel, I, Lozano-Rodríguez, N, Llop-Furquet, G, Sanchis-Artero, L, Cortés-Castell, E, Rizo-Baeza, M, Cortés-Rizo, X
Nutrients. 2023;15(7)
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Coronavirus Disease 2019 (COVID-19), has spread worldwide, reaching pandemic proportions. The symptoms caused by COVID-19 disease are nonspecific and may range from asymptomatic to severe pneumonia and death. The aim of this study was to evaluate the potential effect of a food supplement (probiotics, prebiotics, vitamin D, zinc and selenium) in patients admitted with COVID-19. This study was a prospective, randomised, non-blinded clinical trial. A total of 162 patients were enrolled at Sagunto Hospital, 42.0% of whom were women. Participants were assigned to one of the two groups: probiotic or control group. Results showed that higher mortality was found in men, older patients and those with severe radiological involvement. Furthermore, administration of the food supplement product Gasteel Plus®, as an adjuvant to the treatment established in the hospital for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated pneumonia, reduced the duration of digestive symptoms and hospital stay in patients with mild–moderate pulmonary involvement. Authors conclude that their findings demonstrate the importance of considering the use of the food supplement under review in the prevention and treatment of SARS-CoV-2, including severe cases, which showed no side effects.
Abstract
BACKGROUND COVID-19 disease is a serious global health problem. Few treatments have been shown to reduce mortality and accelerate time to recovery. The aim of this study was to evaluate the potential effect of a food supplement (probiotics, prebiotics, vitamin D, zinc and selenium) in patients admitted with COVID-19. METHODS A prospective randomized non-blinded clinical trial was conducted in a sample of 162 hospitalized patients diagnosed with COVID-19 recruited over eight months. All patients received standard treatment, but the intervention group (n = 67) was given one food supplement stick daily during their admission. After collecting the study variables, a statistical analysis was performed comparing the intervention and control groups and a multivariate analysis controlling for variables that could act as confounding factors. RESULTS ROC curve analysis with an area under the curve (AUC) value of 0.840 (p < 0.001; 95%CI: 0.741-0.939) of the food supplement administration vs. recovery indicated good predictive ability. Moreover, the intervention group had a shorter duration of digestive symptoms compared with the control group: 2.6 ± 1.3 vs. 4.3 ± 2.2 days (p = 0.001); patients with non-severe disease on chest X-ray had shorter hospital stays: 8.1 ± 3.9 vs. 11.6 ± 7.4 days (p = 0.007). CONCLUSIONS In this trial, the administration of a food supplement (Gasteel Plus®) was shown to be a protective factor in the group of patients with severe COVID-19 and allowed early recovery from digestive symptoms and a shorter hospital stay in patients with a normal-mild-moderate chest X-ray at admission (ClinicalTrials.gov number, NCT04666116).
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Effect of a Hop Extract Standardized in 8-Prenylnaringenin on Bone Health and Gut Microbiome in Postmenopausal Women with Osteopenia: A One-Year Randomized, Double-Blind, Placebo-Controlled Trial.
Lecomte, M, Tomassi, D, Rizzoli, R, Tenon, M, Berton, T, Harney, S, Fança-Berthon, P
Nutrients. 2023;15(12)
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Osteoporosis is a bone condition characterized by weakened and brittle bones, leading to an increased risk of fractures. Oestrogens play a vital role in maintaining bone health, whereby oestrogen deficiency elevates the risk of osteoporosis and fractures, particularly in menopausal women due to the decline in oestrogen levels. Phytoestrogens, plant-derived compounds capable of interacting with human oestrogen receptors, have presented an intriguing non-pharmaceutical avenue for preventing bone loss. Other phytoestrogens have received some attention in the field, however, limited human research exists on prenylflavonoids, a phytoestrogens found in hops (Humulus lupulus). This randomized, double-blinded, placebo-controlled trial aimed to investigate the effects of a year-long supplementation of standardised hop extract (8-PN) Lifenol® on bone mineral density in postmenopausal women. Additionally, the study explored potential mechanisms, particularly focusing on changes in gut bacteria. Notably, gut bacteria play a role in bone metabolism and the pathogenesis of osteoporosis. They are also, along with the liver, responsible for converting hops phenols into active phytoestrogenic compounds. The trial was completed by 95 postmenopausal, women with Osteopenia aged 50 to 85. They all received calcium and vitamin D3 tablets in addition either a hop extract (100mcg) or a placebo for 48 weeks. Changes were monitored using DXA scans for bone mineral density (BMD) and bone metabolism, blood samples for markers for bone health, a quality of life questionnaire, gut microbiome testing, and tests for short-chain fatty acid (SCFA) levels. In conclusion, the intake of hop extract confirmed a previously observed trend of a slight increase in total bone mineral density (BMD), in addition to the benefits linked to calcium and vitamin D supplementation. Although there were no significant changes in the composition of gut bacteria and SCFA levels, the hop extract candidates had a higher abundance of specific genera associated with total body BMD, suggesting a potential positive impact. Larger studies are required to validate these findings.
Abstract
Estrogen deficiency increases the risk of osteoporosis and fracture. The aim of this study was to investigate whether a hop extract standardized in 8-prenylnaringenin (8-PN), a potent phytoestrogen, could improve bone status of osteopenic women and to explore the gut microbiome roles in this effect. In this double-blind, placebo-controlled, randomized trial, 100 postmenopausal, osteopenic women were supplemented with calcium and vitamin D3 (CaD) tablets and either a hop extract (HE) standardized in 8-PN (n = 50) or a placebo (n = 50) for 48 weeks. Bone mineral density (BMD) and bone metabolism were assessed by DXA measurements and plasma bone biomarkers, respectively. Participant's quality of life (SF-36), gut microbiome composition, and short-chain fatty acid (SCFA) levels were also investigated. In addition to the CaD supplements, 48 weeks of HE supplementation increased total body BMD (1.8 ± 0.4% vs. baseline, p < 0.0001; 1.0 ± 0.6% vs. placebo, p = 0.08), with a higher proportion of women experiencing an increase ≥1% compared to placebo (odds ratio: 2.41 ± 1.07, p < 0.05). An increase in the SF-36 physical functioning score was observed with HE versus placebo (p = 0.05). Gut microbiome α-diversity and SCFA levels did not differ between groups. However, a higher abundance of genera Turicibacter and Shigella was observed in the HE group; both genera have been previously identified as associated with total body BMD. These results suggest that an 8-PN standardized hop extract could beneficially impact bone health of postmenopausal women with osteopenia.
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The Malnutritional Status of the Host as a Virulence Factor for New Coronavirus SARS-CoV-2.
Briguglio, M, Pregliasco, FE, Lombardi, G, Perazzo, P, Banfi, G
Frontiers in medicine. 2020;7:146
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This opinion article explores the role of an individual’s nutrition status when subjected to infection by viruses, in particular Covid-19. Distinction is made between the susceptibility to infection in the first instance and the ability to persist in fighting infection once it is established. For Covid-19, it is argued that a healthier nutritional status, in particular Vitamins A, B, C, D and E, iron selenium and zinc, will lower susceptibility to infection, lower the severity of the virus and therefore reduce the length of time an individual has to find reserves to fight the virus. More severe cases of Covid-19 infection also often include gastro-intestinal symptoms which further exacerbate nutritional status with lowered appetite. The authors conclude that malnourished individuals may be more susceptible to Covid-19 infection and that nutritional support is vital in severe cases. The article includes a useful diagram of both hyponutrition and hypernutrition and possible impacts of Covid-19.
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Nutritional Interventions in the Management of Fibromyalgia Syndrome.
Pagliai, G, Giangrandi, I, Dinu, M, Sofi, F, Colombini, B
Nutrients. 2020;12(9)
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Fibromyalgia (FM) is a chronic pain condition, often presenting with widespread body pain, joint stiffness, sleep disorders, depression, anxiety, gastrointestinal and cognitive complaints. Despite being common, the cause of FM is not well understood. In the absence of effective treatments, the current management of FM involves a multidisciplinary approach utilizing pharmacological and non-pharmacological interventions. Growing evidence suggests a role for nutrition as a complementary strategy for FM management. This brief review summarises the possible impact of nutritional supplements and dietary interventions on FM. Previous reviews concluded that vitamin and mineral deficiencies themselves are unlikely to be significant in the development of FM. Yet, a few interventional studies investigating the use of Vitamin D, magnesium, iron and probiotics showed promising results. To date, there is no or limited evidence for the use of Vitamin C, E, selected amino acids, botanical or antioxidant supplements. Food-wise the inclusion of quality olive oil and the grain Khorasan proved helpful on FM presentation, whilst findings around the role of dietary monosodium glutamate and aspartame seem mixed. Regarding diet patterns, gluten-free, low-calorie, vegetarian, vegan, raw food or Mediterranean diets were all associated with improvement of symptoms. Equally a FODMAP diet can aid FM associated digestive complaints due to the significant overlap of Irritable Bowel Syndrome with FM. The authors concluded that the clinical application of dietary supplements in the management of FM remains controversial. Yet, dietary interventions appear to be an effective tool in the management of FM. Since various diet interventions demonstrated benefits, dietary adequacy and weight loss may be most critical from a clinical perspective.
Abstract
Fibromyalgia (FM) is a multifactorial syndrome of unknown etiology, characterized by widespread chronic pain and various somatic and psychological manifestations. The management of FM requires a multidisciplinary approach combining both pharmacological and nonpharmacological strategies. Among nonpharmacological strategies, growing evidence suggests a potential beneficial role for nutrition. This review summarizes the possible relationship between FM and nutrition, exploring the available evidence on the effect of dietary supplements and dietary interventions in these patients. Analysis of the literature has shown that the role of dietary supplements remains controversial, although clinical trials with vitamin D, magnesium, iron and probiotics' supplementation show promising results. With regard to dietary interventions, the administration of olive oil, the replacement diet with ancient grains, low-calorie diets, the low FODMAPs diet, the gluten-free diet, the monosodium glutamate and aspartame-free diet, vegetarian diets as well as the Mediterranean diet all appear to be effective in reducing the FM symptoms. These results may suggest that weight loss, together with the psychosomatic component of the disease, should be taken into account. Therefore, although dietary aspects appear to be a promising complementary approach to the treatment of FM, further research is needed to provide the most effective strategies for the management of FM.
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Vitamin B12 Status Upon Short-Term Intervention with a Vegan Diet-A Randomized Controlled Trial in Healthy Participants.
Lederer, AK, Hannibal, L, Hettich, M, Behringer, S, Spiekerkoetter, U, Steinborn, C, Gründemann, C, Zimmermann-Klemd, AM, Müller, A, Simmet, T, et al
Nutrients. 2019;11(11)
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Veganism is growing in western societies and with it comes an increased risk of vitamin B12 deficiency which is principally found in animal products. Vitamin B12 is essential for multiple biological functions including DNA synthesis, digestive function and detoxification processes. It can take 2-5 years to exhaust natural stores of B12 within the body so deficiency risk is considered safe. This 2017 randomised control trial compared vitamin B12 status in 53 healthy omnivore subjects with 26 participants following an unsupplemented vegan diet for 4 weeks and the remaining 27 participants a meat-rich diet. The aim of the study was to answer two questions; (a) Do vitamin B12 markers respond to short-term dietary intervention with a meat-rich or a plant-based diet? and (b) Do meat-rich and vegan diets have an impact on plasma markers of inflammation and cardiovascular disease? Blood and urine samples were taken before and after the 4-week dietary protocol to also measure vitamin D status, Folate and Homocysteine levels as a marker for inflammation. The serum vitamin B12 levels (indicative of dietary B12) dropped significantly from 362.9 +/- 110.9 ng/mL to 296.1 +/- 94.1 ng/mL in the Vegan Diet group (p < 0.001) and remained stable in the Meat Diet group. Other markers measuring cellular B12 metabolism did not significantly vary. The short-term nature of the trial demonstrated rapid decrease in holo-TC, the bioactive form of vitamin B12 in plasma. The other blood and urinary markers demonstrated benefits to plant-based eating including reduced cholesterol intake and adequate profiles of nutrient and micronutrient status.
Abstract
Vegans are at an increased risk for certain micronutrient deficiencies, foremost of vitamin B12. Little is known about the short-term effects of dietary change to plant-based nutrition on vitamin B12 metabolism. Systemic biomarkers of vitamin B12 status, namely, serum vitamin B12 and holotranscobalamin, may respond quickly to a reduced intake of vitamin B12. To test this hypothesis, 53 healthy omnivore subjects were randomized to a controlled unsupplemented vegan diet (VD, n = 26) or meat-rich diet (MD, n = 27) for 4 weeks. Vitamin B12 status was examined by measurement of serum vitamin B12, holotranscobalamin (holo-TC), methylmalonic acid (MMA) and total plasma homocysteine (tHcy). Holo-TC decreased significantly in the VD compared to the MD group after four weeks of intervention, whereas metabolites MMA and tHcy were unaffected. Body weight remained stable in both groups. VD intervention led to a significant reduction of cholesterol intake, and adequate profiles of nutrient and micronutrient status. Lower intake of vitamin B12 was observed in VD, which was mirrored by a lower concentration of serum vitamin B12 and reduced holo-TC after 4 weeks. Plasma holo-TC may be a fast-responding biomarker to monitor adequate supply of vitamin B12 in plant-based individuals.
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Gut microbiota alterations associated with reduced bone mineral density in older adults.
Das, M, Cronin, O, Keohane, DM, Cormac, EM, Nugent, H, Nugent, M, Molloy, C, O'Toole, PW, Shanahan, F, Molloy, MG, et al
Rheumatology (Oxford, England). 2019;58(12):2295-2304
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Osteoporosis, characterised by reduced bone density or ‘brittle bones’ affects a significant number of individuals over the age of 50 worldwide. Contributing factors include calcium and vitamin D deficiency and the presence of other inflammatory conditions. The composition of gut bacteria, the gut microbiome, plays an important role in immune activity and changes in composition have been associated with other inflammatory conditions. This cohort study of 181 individuals at high risk of reduced bone density and fractures, aimed to determine whether different gut microbiota composition is associated with bone density. Dexa scans and faecal samples were used as part of the assessment and confounding factors of diet, BMI, supplementation and medication were included in the analysis. The authors of the study found 6 species of gut bacteria that were significantly altered in numbers in the groups with osteoporosis and osteopenia, after controlling for confounding factors, and suggest that they could be used as markers of disease risk or progression and as a therapeutic target. Nutrition Practitioners working with bone density can focus on supporting the gut microbiome as part of their nutrition protocols.
Abstract
OBJECTIVE To investigate compositional differences in the gut microbiota associated with bone homeostasis and fractures in a cohort of older adults. METHODS Faecal microbiota profiles were determined from 181 individuals with osteopenia (n = 61) or osteoporosis (n = 60), and an age- and gender-matched group with normal BMD (n = 60). Analysis of the 16S (V3-V4 region) amplicon dataset classified to the genus level was used to identify significantly differentially abundant taxa. Adjustments were made for potential confounding variables identified from the literature using several statistical models. RESULTS We identified six genera that were significantly altered in abundance in the osteoporosis or osteopenic groups compared with age- and gender-matched controls. A detailed study of microbiota associations with meta-data variables that included BMI, health status, diet and medication revealed that these meta-data explained 15-17% of the variance within the microbiota dataset. BMD measurements were significantly associated with alterations in the microbiota. After controlling for known biological confounders, five of the six taxa remained significant. Overall microbiota alpha diversity did not correlate to BMD in this study. CONCLUSION Reduced BMD in osteopenia and osteoporosis is associated with an altered microbiota. These alterations may be useful as biomarkers or therapeutic targets in individuals at high risk of reductions in BMD. These observations will lead to a better understanding of the relationship between the microbiota and bone homeostasis.
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25-Hydroxyvitamin D Measurement in Human Hair: Results from a Proof-of-Concept study.
Zgaga, L, Laird, E, Healy, M
Nutrients. 2019;11(2)
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Vitamin-D deficiency is now considered to effect over 1 billion people world-wide and has known health implications including bone pathologies, immune dysfunction and metabolic diseases. It is thought that vitamin-D deficiency is increasing amongst the population due to our indoor lifestyles and increased use of sunscreens. The current method used to determine vitamin-D status is by measuring the concentration within blood circulation. Although considered accurate, this method can prove inconvenient and costly, especially for those requiring repeat or regular monitoring. A far simpler means of measurement is through hair analysis, although this method is in its infantry. The aim of this study was to investigate whether this method shows consistent markers in vitamin-D status which correlate to those of blood samples and whether hair analysis has potential for further research. The subjects in this study were the three authors who compared vitamin-D markers within their own hair to the markers within their blood serum concentrations. They found that although it is not possible to rely solely on hair analysis to measure vitamin-D status, it is possible to gain a picture of vitamin-D status historically, which can aid epidemiological research. Supplemental intake could also be monitored through longitudinal methods. Whilst the results were varied and inconclusive, the authors do suggest that there is scope for future research. Variations need to be accounted for, such as hair colour, age related differences plus methods of extracting the vitamin from the hair shaft.
Abstract
Vitamin D deficiency has been implicated in numerous human diseases leading to an increased interest in assessing vitamin D status. Consequentially, the number of requests for vitamin D measurement keeps dramatically increasing year-on-year. Currently, the recognised best marker of vitamin D status is the concentration of the 25-hydroxyvitamin D (25(OH)D₃) in the blood circulation. While providing an accurate estimate of vitamin D status at the point in time of sampling, it cannot account for the high variability of 25(OH)D₃ concentration. In this proof of concept study we set out to provide evidence that 25(OH)D₃ can be extracted from hair samples in a similar fashion to steroid hormones. Two of the authors (L.Z. and M.H.) provided hair samples harvested from the crown area of the scalp and the third author (E.L.) provided beard samples. These samples, cut into 1 cm lengths, were weighed, washed and dried. 25(OH)D was extracted using a previously published steroid hormones extraction procedure. Blood samples were taken from the subjects at the same time all tissue samples were analysed using liquid-chromatography mass spectrometry. Hair samples showed presence of quantifiable 25(OH)D₃ with concentrations ranging from 11.9⁻911 pg/mg. The beard sample had a concentration of 231 pg/mg. Serum levels of 25(OH)D₃ ranged from 72⁻78 nmol/L. The results presented here confirm the feasibility of measuring 25(OH)D₃ in hair samples. The findings warrant further validation and development and have the potential to yield valuable information relating to temporal trends in vitamin D physiology.
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Vitamin D: Nutrient, Hormone, and Immunomodulator.
Sassi, F, Tamone, C, D'Amelio, P
Nutrients. 2018;10(11)
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Vitamin D is well known for its role in controlling bone metabolism. However, Vitamin D deficiency has been reported in conditions associated with inflammation and disordered immunity, such as diabetes and asthma. This review article summarises the evidence on the potential of Vitamin D in modulating the immune system. The authors present evidence of Vitamin D as a regulator of the innate immune system (first line, rapid defence against infection); discuss the relationship between Vitamin D and the gut microbiota; and examine evidence on Vitamin D and the adaptive or acquired immune system (second line, delayed defence against infection). The authors conclude that the evidence is strong in relation to Vitamin D and the innate immune system and more controversial in relation to the acquired immune system. There is no general consensus as yet on the desired level of 25(OH)D3 to modulate the immune system and further studies are needed to provide clarity. Nutrition Practitioners wishing to optimise Vitamin D levels could follow expert agreement of Vitamin D levels of 75-125nmol/l, which has been shown to provide skeletal effects without toxicity.
Abstract
The classical functions of vitamin D are to regulate calcium-phosphorus homeostasis and control bone metabolism. However, vitamin D deficiency has been reported in several chronic conditions associated with increased inflammation and deregulation of the immune system, such as diabetes, asthma, and rheumatoid arthritis. These observations, together with experimental studies, suggest a critical role for vitamin D in the modulation of immune function. This leads to the hypothesis of a disease-specific alteration of vitamin D metabolism and reinforces the role of vitamin D in maintaining a healthy immune system. Two key observations validate this important non-classical action of vitamin D: first, vitamin D receptor (VDR) is expressed by the majority of immune cells, including B and T lymphocytes, monocytes, macrophages, and dendritic cells; second, there is an active vitamin D metabolism by immune cells that is able to locally convert 25(OH)D₃ into 1,25(OH)₂D₃, its active form. Vitamin D and VDR signaling together have a suppressive role on autoimmunity and an anti-inflammatory effect, promoting dendritic cell and regulatory T-cell differentiation and reducing T helper Th 17 cell response and inflammatory cytokines secretion. This review summarizes experimental data and clinical observations on the potential immunomodulating properties of vitamin D.