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The Impact of Vitamin D Supplementation on the IFNγ-IP10 Axis in Women with Hashimoto's Thyroiditis Treated with Levothyroxine: A Double-blind Randomized Placebo-controlled Trial.
Robat-Jazi, B, Mobini, S, Chahardoli, R, Mansouri, F, Nodehi, M, Esfahanian, F, Saboor Yaraghi, AA
Iranian journal of allergy, asthma, and immunology. 2022;21(4):407-417
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Hashimoto’s thyroiditis is an autoimmune disease characterized by the presence of antibodies against thyroid proteins such as thyroperoxidase (TPO) and thyroglobulin (TG), the local accumulation of inflammatory cells and immune-mediated destruction of the thyroid gland. Disease manifestation is due to a genetic disposition but is also influenced by several environmental factors, including stress, smoking, infections, and levels of nutrients like iodine, selenium and vitamin D. Many cells of the immune system have receptors for Vitamin D and thus have the potential to be influenced by Vitamin D. Indeed, numerous findings demonstrated that vitamin D can exert anti-inflammatory effects on the immune system. This double-blind, randomized, placebo-controlled trial investigated 40 Hashimoto's thyroiditis subjects and the effect of Vitamin D supplementation on various markers of the immune system that mediate the inflammatory response as part of the interferon-gamma-induced protein 10 (IFNγ-IP10) axis. 20 of the enrolled candidates received 50000 IU of Vitamin D (cholecalciferol) once a week – an equivalent to about 7140 IU per day - over three months. The other half received a placebo. All candidates had a fixed dose of thyroid hormone replacement levothyroxine for the duration of the trial. Before and after the intervention several blood biomarkers were investigated relating to Vitamin D levels, D-receptors, immune activity and inflammation. Upon completion of the trial, the intervention group who supplemented Vitamin D had significantly higher Vitamin D levels, which had increased from an average of 25.29 ng/ml to 50.65ng/ml. In addition, several inflammatory factors were significantly decreased. These findings affirmed Vitamin D’s ability to favourably regulate the IFNγ-IP10 axis, which could slow disease progression. This effect may also be useful for the management of other autoimmune disorders involving IP10 overproduction, which attracts other inflammatory cells. More studies in larger groups would help to get more information on other variables not considered in this trial.
Abstract
Hashimoto's thyroiditis (HT) results from chemoattraction of inflammatory cells toward the thyroid gland by inducing the production of interferon-gamma (IFNγ)-induced protein 10 (IP10) by T helper (Th) 1 cells. Vitamin D may suppress the IFNγ-IP10 axis, but this new function of vitamin D has not yet been investigated in HT patients. In an intervention and control group, patients received 50000 IU cholecalciferol or placebo every week for three months, respectively. The CD4+ T cells of 40 patients were isolated, and the mRNA expression levels of vitamin D receptor (VDR), peroxisome proliferator-activated receptors (PPAR)-α, and PPAR-γ genes were determined by real-time PCR. ELISA method was used to determine serum levels of vitamin D, tumor necrosis factor-alpha (TNF-α), IFN-γ, and IP10. Vitamin D levels in the intervention group were significantly higher than in the placebo group after supplementation. PPAR-α and PPAR-γ gene expression levels did not differ significantly between the two groups. The serum levels of IP10, IFNγ, and TNF-α decreased significantly in the vitamin D group, as well as in the placebo group. During this study, vitamin D levels significantly increased in the intervention group and inflammatory factors decreased. Based on the similar results obtained in the placebo group, further studies with larger sample sizes and longer intervention times are recommended.
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The effect of an exercise program in pregnancy on vitamin D status among healthy, pregnant Norwegian women: a randomized controlled trial.
Gustafsson, MK, Romundstad, PR, Stafne, SN, Helvik, AS, Stunes, AK, Mørkved, S, Salvesen, KÅ, Thorsby, PM, Mosti, MP, Syversen, U
BMC pregnancy and childbirth. 2019;19(1):76
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Pregnancy represents a unique metabolic state with adaptive physiological changes including the vitamin D endocrine system. The aim of this study was to explore a potential relation between regular exercise in pregnancy and the vitamin D endocrine system. This study is a two-armed, two-centre randomised controlled study. The health effects of a 12-week exercise program during pregnancy (pregnant women n = 855) was compared with standard prenatal care. Results show higher levels of total, free and bioavailable Vitamin D in the exercise group indicating that exercise in pregnancy may affect vitamin D status positively. Authors conclude by highlighting that women with uncomplicated pregnancies should be encouraged to perform regular exercise.
Abstract
BACKGROUND Vitamin D insufficiency is common in pregnant women worldwide. Regular prenatal exercise is considered beneficial for maternal and fetal health. There is a knowledge gap regarding the impact of prenatal exercise on maternal vitamin D levels. The objective of this study was to investigate whether a prenatal exercise program influenced serum levels of total, free and bioavailable 25-hydroxyvitamin D (25(OH)D) and related parameters. This is a post hoc analysis of a randomized controlled trial with gestational diabetes as the primary outcome. METHODS Healthy, pregnant women from two Norwegian cities (Trondheim and Stavanger) were randomly assigned to a 12-week moderate-intensity exercise program (Borg perceived rating scale 13-14) or standard prenatal care. The intervention group (n = 429) underwent exercise at least three times weekly; one supervised group training and two home based sessions. The controls (n = 426) received standard prenatal care, and exercising was not denied. Training diaries and group training was used to promote compliance and evaluate adherence. Serum levels of 25(OH)D, parathyroid hormone, calcium, phosphate, magnesium and vitamin D-binding protein were measured before (18-22 weeks' gestation) and after the intervention (32-36 weeks' gestation). Free and bioavailable 25(OH)D concentrations were calculated. Regression analysis of covariance (ANCOVA) was applied to assess the effect of the training regime on each substance with pre-intervention levels as covariates. In a second model, we also adjusted for study site and sampling month. Intention-to-treat principle was used. RESULTS A total of 724 women completed the study. No between-group difference in serum 25(OH)D and related parameters was identified by ANCOVA using baseline serum levels as covariates. The second model revealed a between-group difference in levels of 25(OH)D (1.9, 95% CI 0.0 to 3.8 nmol/L; p = 0.048), free 25(OH)D (0.55, 95% CI 0.10 to 0.99 pmol/L; p = 0.017) and bioavailable 25(OH)D (0.15 95% CI 0.01 to 0.29 nmol/L; p = 0.036). No serious adverse events related to regular exercise were seen. CONCLUSION This study, a post hoc analysis, indicates that exercise may affect vitamin D status positively, and emphasizes that women with uncomplicated pregnancies should be encouraged to perform regular exercise. TRIAL REGISTRATION ClinicalTrials.gov: NCT00476567 , registered May 22, 2007.
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Daily Nutritional Supplementation with Vitamin D₃ and Phenylbutyrate to Treatment-Naïve HIV Patients Tested in a Randomized Placebo-Controlled Trial.
Ashenafi, S, Amogne, W, Kassa, E, Gebreselassie, N, Bekele, A, Aseffa, G, Getachew, M, Aseffa, A, Worku, A, Hammar, U, et al
Nutrients. 2019;11(1)
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Poor nutritional status is common among human immunodeficiency virus (HIV)-infected patients including vitamin D (vitD3) deficiency. VitD3 together with phenylbutyrate (PBA) can induce an antimicrobial peptide called cathelicidin which has anti-viral properties. VitD3 and PBA can also enhance autophagy, a physiological process known to enhance destruction of intracellular viruses. The aim of this double-blind, placebo-controlled trial was to evaluate whether vitD3 + PBA could reduce viral replication and restore immune and nutritional status in HIV infection. 173 previously untreated HIV patients were randomised to receive either 5000 IU vitD3 and 500 mg PBA or placebos for 16 weeks with follow-up of a further 8 weeks. Most subjects had low plasma vitD3 levels at baseline which increased significantly in the vitD3 + PBA group compared with placebo at weeks 4, 8 and 16, indicating good compliance and response to the treatment. There were no statistical differences in any of the measured outcomes, including viral load, CD4 cells, CD8 cells and body mass index, between treatment and placebo group at any point during the study and follow-up.
Abstract
Poor nutritional status is common among human immunodeficiency virus (HIV)-infected patients including vitamin D (vitD₃) deficiency. We conducted a double-blinded, randomized, and placebo-controlled trial in Addis Ababa, Ethiopia, to investigate if daily nutritional supplementation with vitD₃ (5000 IU) and phenylbutyrate (PBA, 2 × 500 mg) could mediate beneficial effects in treatment-naïve HIV patients. Primary endpoint: the change in plasma HIV-1 comparing week 0 to 16 using modified intention-to-treat (mITT, n = 197) and per-protocol (n = 173) analyses. Secondary endpoints: longitudinal HIV viral load, T cell counts, body mass index (BMI), middle-upper-arm circumference (MUAC), and 25(OH)D₃ levels in plasma. Baseline characteristics were detectable viral loads (median 7897 copies/mL), low CD4⁺ (median 410 cells/µL), and elevated CD8⁺ (median 930 cells/µL) T cell counts. Most subjects were vitD₃ deficient at enrolment, but a gradual and significant improvement of vitD₃ status was demonstrated in the vitD₃ + PBA group compared with placebo (p < 0.0001) from week 0 to 16 (median 37.5 versus 115.5 nmol/L). No significant changes in HIV viral load, CD4⁺ or CD8⁺ T cell counts, BMI or MUAC could be detected. Clinical adverse events were similar in both groups. Daily vitD₃ + PBA for 16 weeks was well-tolerated and effectively improved vitD₃ status but did not reduce viral load, restore peripheral T cell counts or improve BMI or MUAC in HIV patients with slow progressive disease. Clinicaltrials.gov NCT01702974.
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The effects of two vitamin D regimens on ulcerative colitis activity index, quality of life and oxidant/anti-oxidant status.
Karimi, S, Tabataba-Vakili, S, Yari, Z, Alborzi, F, Hedayati, M, Ebrahimi-Daryani, N, Hekmatdoost, A
Nutrition journal. 2019;18(1):16
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Ulcerative colitis (UC) is a type of Inflammatory bowel disease (IBD), which involves the immune system attacking healthy bowel tissue. Vitamin D has an effect on the immune response, possibly by reducing inflammation, promoting immune system tolerance and improving the health of the bowel lining. Several studies have found a link between vitamin D deficiency and IBD, but the optimum dosage for vitamin D supplementation is not yet known. The aim of this study was to look at the effects of two dosages of vitamin D supplementation on serum vitamin D, total antioxidant capacity (TAC), total oxidant status (TOS), quality of life, and disease activity index in patients with UC. In this double blind randomised clinical trial, 50 patients with mild to moderate UC received either 1,000 (‘low dose’) or 2,000 (‘high dose’) IU/day of vitamin D for 12 weeks. At the end of study, serum 25-OHD levels had significantly increased in the high dose group and the increase was significantly more (6.7 ± 3.8 ng/mL) than the low dose (0.2 ± 0.5 ng/mL) group. Serum TOS concentration decreased significantly (- 0.37 ± 0.26) only in the high dose group. There was no significant change in serum TAC between two groups during the study. The quality of life score significantly improved in the high dose group compared to the low dose group and disease activity index score reduce in both groups but was significant only in the high dose group. The authors concluded that 2,000 IU a day of vitamin D can increase serum 25-OHD concentration and quality of life, and reduce disease activity in UC patients with vitamin D deficiency. They recommend that all patients with UC should have their vitamin D status assessed because they may benefit from vitamin D therapy.
Abstract
BACKGROUND The optimum dosage for vitamin D supplementation has not yet been elucidated in patients with Ulcerative colitis (UC). The aim of this study was to investigate the effects of two vitamin D regimens in UC patients with vitamin D deficiency. METHODS In this double blind randomized clinical trial, 50 patients with mild to moderate UC, who met inclusion criteria, received either 1000 or 2000 IU/day of vitamin D (as low dose or high dose group, respectively) for 12 weeks. Serum 25-hydroxy vitamin D (25-OHD) level, total antioxidant capacity (TAC), and Total Oxidant Status (TOS), the inflammatory bowel disease questionnaire - 9 (IBDQ-9) score and the Simple Clinical Colitis Activity Index Questionnaire (SCCAI) score were assessed before and after intervention. RESULTS At the end of study, serum 25-OHD levels significantly increased in the high dose group (P < 0.001) and the increase was significantly more than low dose group (6.7 ± 3.8 ng/mL in the high dose group versus 0.2 ± 0.5 ng/mL in the low dose group) (P < 0.001). Serum TOS concentration decreased significantly (- 0.37 ± 0.26) only in the high dose group (P value = 0.023). There was no statistically significant change in serum TAC between two groups during the study. IBDQ-9 mean score significantly increased in high dose group compared to the low dose group (P value = 0.001) and SCCAI score in both groups reduced (- 2.58 ± 2.16 and - 0.9 ± 0.3 in high dose and low dose respectively), while this reduction was significant only in the high dose group (P value ≥0.001). CONCLUSION Our results indicate that 2000 IU daily dose of vitamin D can increase serum 25-OHD concentration, and quality of life, while it reduces disease activity in UC patients with vitamin D deficiency. We recommend assessment of the vitamin D status in all patients with UC because they may benefit from vitamin D therapy.
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A Randomized, Controlled Trial of Vitamin D Supplementation on Cardiovascular Risk Factors, Hormones, and Liver Markers in Women with Polycystic Ovary Syndrome.
Javed, Z, Papageorgiou, M, Deshmukh, H, Kilpatrick, ES, Mann, V, Corless, L, Abouda, G, Rigby, AS, Atkin, SL, Sathyapalan, T
Nutrients. 2019;11(1)
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Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting more than 10% of women of reproductive age and is associated with an increase in cardiovascular risk factors, metabolic syndrome, cardiovascular diseases and non-alcoholic fatty liver disease (NAFLD). The aim of this double-blind, randomized, placebo-controlled study was to explore the effects of vitamin D supplementation on cardiovascular risk factors, hormones, glucose metabolism and markers of liver injury and fibrosis in overweight and obese vitamin D deficient women with PCOS. 40 participants were randomised to take either 3200iu vitamin D or placebo daily for 3 months. Vitamin D levels significantly increased over the three months in both groups but statistically significantly more so in women receiving vitamin D compared to placebo. Women receiving vitamin D had normal vitamin D levels after three months of supplementation whilst women in the placebo group remained within the insufficiency range. The only significant improvement that was statistically significantly better in the vitamin D group compared to placebo group was a decrease in alanine transaminase (ALT, a marker of liver function). Weak improvements in insulin sensitivity and liver fibrosis markers were also observed but these were not statistically significantly better than in the placebo group.
Abstract
Polycystic ovary syndrome (PCOS) increases the risk of metabolic syndrome and non-alcoholic-fatty-liver disease (NAFLD). Vitamin D supplementation may exert positive effects on liver biochemistry in patients with NAFLD; however, its effects on PCOS are unknown. This randomized, double-blind, placebo-controlled study explored the effect of vitamin D supplementation on cardiovascular risk factors (high-sensitivity C-reactive protein (hs-CRP), weight, body mass index (BMI), lipid profile, glucose levels, insulin levels, the homeostatic model assessment-insulin resistance (HOMA-IR), hormones (free androgen index (FAI), testosterone, sex hormone binding globulin (SHBG), and liver markers (alanine aminotransferase (ALT), hyaluronic acid (HA), N-terminal pro-peptide of type III procollagen (PIIINP), tissue inhibitor of metallo-proteinases-1 (TIMP-1), and the enhanced liver fibrosis (ELF) score). Forty women with PCOS were recruited and randomized to vitamin D (3200 IU) or placebo daily for 3 months. All outcomes were measured at baseline and 3 months follow-up (FU). Greater increases in vitamin D levels were shown in the supplementation group (vitamin D, baseline: 25.6 ± 11.4 nmol/L, FU: 90.4 ± 19.5 nmol/L vs. placebo, baseline: 30.9 ± 11.1 nmol/L, FU: 47.6 ± 20.5 nmol/L, p < 0.001). Between groups comparisons (% baseline change) revealed significant differences in ALT (p = 0.042) and a weak effect indicating a greater reduction in the HOMA-IR in the vitamin D group (p = 0.051). No further between group differences were seen in other cardiovascular risk factor, liver markers, or hormones. This study supports beneficial effects of vitamin D supplementation on liver markers and modest improvements in insulin sensitivity in vitamin D deficient women with PCOS.
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Vitamin D Supplementation and Physical Activity of Young Soccer Players during High-Intensity Training.
Skalska, M, Nikolaidis, PT, Knechtle, B, Rosemann, TJ, Radzimiński, Ł, Jastrzębska, J, Kaczmarczyk, M, Myśliwiec, A, Dragos, P, López-Sánchez, GF, et al
Nutrients. 2019;11(2)
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It has been shown that the vitamin D levels in athletes has a significant impact on their neuro-muscular system. The aim of this study was to determine the effect of vitamin D supplementation on physical activity measures among soccer players during small-sided games after an 8-week high-intensity training programme. In this placebo-controlled, double blind study, 36 participants were randomised to receive either placebo or vitamin D (5000 IU) supplementation for 8 weeks. Average distance and intensity was calculated based on four small-sided games. While the supplemented group increased vitamin D levels significantly, improvements in various physical activity measures were not statistically significant. Though the effect size of this trial is low the authors recommend supplementing vitamin D to young soccer players, especially with vitamin D levels are deficient.
Abstract
The aim of this study was to confirm that vitamin D supplementation of young soccer players during eight-week high-intensity training would have a significant effect on their motion activity. The subjects were divided into two groups: the experimental one, which was supplemented with vitamin D (SG, n = 20), and the placebo group (PG, n = 16), which was not supplemented with vitamin D. All the players were subjected to the same soccer training, described as High-Intensity Interval Training (HIIT). The data of the vitamin D status, time motion parameters and heart rate were collected just before and after the intervention. A significant increase in 25(OH)D concentration (119%) was observed in the supplemented group, while the non-supplemented group showed a decrease of 8.4%. Based on the obtained results, it was found that physical activity indicators in the players were significantly improved during small-sided games at the last stage of the experiment. However, taking into account the effect of supplementation with vitamin D, there were no statistically significant differences between the placebo and the supplemented groups; thus, the effect size of the conducted experiment was trivial.
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Vitamin D Supplementation in Pregnancy and Lactation and Infant Growth.
Roth, DE, Morris, SK, Zlotkin, S, Gernand, AD, Ahmed, T, Shanta, SS, Papp, E, Korsiak, J, Shi, J, Islam, MM, et al
The New England journal of medicine. 2018;379(6):535-546
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In Bangladesh, 30% of newborns are small for gestational age and 36% of children under 5-years of age have stunted growth. Some previous studies suggest that supplementing mums-to-be with vitamin D during and/or after pregnancy may improve foetal and infant growth. The aim of this trial was to evaluate the dose-dependent effects of vitamin D supplementation on infant growth in Bangladesh. Over 1,100 pregnant women were split into five groups. One group received no vitamin D (placebo group). Three groups received supplementation from mid pregnancy in doses of 4200 IU, 16,800 IU, and 28,000 IU per week. The fifth group received 28,000 IU vitamin D per week during pregnancy, as well as 28,000 IU weekly for 26 weeks after childbirth. At the start of the study, 64% of women were vitamin D deficient (defined as 25(OH)D<30 nmol/L). The vitamin D status of the women was similar across the groups. Among 1,164 infants assessed at 1 year of age, there were no significant differences across groups in the length-for-age scores. Other anthropometric measures, birth outcomes, and morbidity did not differ significantly across groups. The researchers concluded that maternal vitamin D supplementation from mid pregnancy until birth or until 6 months post-partum did not improve foetal or infant growth. The findings of the study do not support routine vitamin D supplementation in pregnancy or lactation to improve birth outcomes or infant growth, even in communities with endemic vitamin D deficiency and foetal-infant growth restriction.
Abstract
BACKGROUND It is unclear whether maternal vitamin D supplementation during pregnancy and lactation improves fetal and infant growth in regions where vitamin D deficiency is common. METHODS We conducted a randomized, double-blind, placebo-controlled trial in Bangladesh to assess the effects of weekly prenatal vitamin D supplementation (from 17 to 24 weeks of gestation until birth) and postpartum vitamin D supplementation on the primary outcome of infants' length-for-age z scores at 1 year according to World Health Organization (WHO) child growth standards. One group received neither prenatal nor postpartum vitamin D (placebo group). Three groups received prenatal supplementation only, in doses of 4200 IU (prenatal 4200 group), 16,800 IU (prenatal 16,800 group), and 28,000 IU (prenatal 28,000 group). The fifth group received prenatal supplementation as well as 26 weeks of postpartum supplementation in the amount of 28,000 IU (prenatal and postpartum 28,000 group). RESULTS Among 1164 infants assessed at 1 year of age (89.5% of 1300 pregnancies), there were no significant differences across groups in the mean (±SD) length-for-age z scores. Scores were as follows: placebo, -0.93±1.05; prenatal 4200, -1.11±1.12; prenatal 16,800, -0.97±0.97; prenatal 28,000, -1.06±1.07; and prenatal and postpartum 28,000, -0.94±1.00 (P=0.23 for a global test of differences across groups). Other anthropometric measures, birth outcomes, and morbidity did not differ significantly across groups. Vitamin D supplementation had expected effects on maternal and infant serum 25-hydroxyvitamin D and calcium concentrations, maternal urinary calcium excretion, and maternal parathyroid hormone concentrations. There were no significant differences in the frequencies of adverse events across groups, with the exception of a higher rate of possible hypercalciuria among the women receiving the highest dose. CONCLUSIONS In a population with widespread prenatal vitamin D deficiency and fetal and infant growth restriction, maternal vitamin D supplementation from midpregnancy until birth or until 6 months post partum did not improve fetal or infant growth. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT01924013 .).
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Association Between Single Gene Polymorphisms and Bone Biomarkers and Response to Calcium and Vitamin D Supplementation in Young Adults Undergoing Military Training.
Gaffney-Stomberg, E, Lutz, LJ, Shcherbina, A, Ricke, DO, Petrovick, M, Cropper, TL, Cable, SJ, McClung, JP
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. 2017;32(3):498-507
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The risk of stress fracture is increased in initial military training (IMT) largely because of unaccustomed activity, resulting in a change in calcium and vitamin D levels. Genetic polymorphisms are variations in a gene that affect the level of gene expression, and bone metabolism and absorption is impacted by this. The primary aim of this randomised, double-blind, placebo controlled trial was to determine whether genes related to Calcium and vitamin D were associated with markers of bone metabolism in 748 young adults entering military training. Participants were randomised to consume bars between meals that were either supplemented with Calcium and vitamin D or placebo that were matched in taste and appearance. Fasting blood samples were taken before and after the 7- to 9-week IMT programme to assess circulating biomarkers and genes. This study found that genetic polymorphisms related to Calcium and vitamin D were associated with vitamin D status and markers of bone metabolism. It also found that genes could predict change in vitamin D absorption levels. Based on these results, the authors conclude this study provides novel insight that helps further understanding between genetics, environment and bone metabolism.
Abstract
Initial military training (IMT) is associated with increased stress fracture risk. In prior studies, supplemental calcium (Ca) and vitamin D provided daily throughout IMT reduced stress fracture incidence, suppressed parathyroid hormone (PTH), and improved measures of bone health compared with placebo. Data were analyzed from a randomized, double-blind, placebo-controlled trial to determine whether single-nucleotide polymorphisms (SNPs) in Ca and vitamin D-related genes were associated with circulating biomarkers of bone metabolism in young adults entering IMT, and whether responses to Ca and vitamin D supplementation were modulated by genotype. Associations between SNPs, including vitamin D receptor (VDR), vitamin D binding protein (DBP), and 1-alpha-hydroxylase (CYP27B1), and circulating biomarkers were measured in fasting blood samples from volunteers (n = 748) starting IMT. Volunteers were block randomized by race and sex to receive Ca (2000 mg) and vitamin D (1000 IU) or placebo daily throughout Army or Air Force IMT (7 to 9 weeks). Total Ca and vitamin D intakes were calculated as the sum of supplemental intake based on intervention compliance and dietary intake. Relationships between SNPs, Ca, and vitamin D intake tertile and change in biomarkers were evaluated in trial completers (n = 391). At baseline, the minor allele of a DBP SNP (rs7041) was positively associated with both 25OHD (B = 4.46, p = 1.97E-10) and 1,25(OH)2 D3 (B = 9.63, p < 0.001). Combined genetic risk score (GRS) for this SNP and a second SNP in the VDR gene (rs1544410) was inversely associated with baseline 25OHD (r = -0.28, p < 0.001) and response to Ca and vitamin D intake differed by GRS (p < 0.05). In addition, presence of the minor allele of a second VDR SNP (rs2228570) was associated with lower P1NP (B = -4.83, p = 0.04) and osteocalcin (B = -0.59, p = 0.03). These data suggest that VDR and DBP SNPs are associated with 25OHD status and bone turnover and those with the highest GRS require the greatest vitamin D intake to improve 25OHD during IMT. © 2016 American Society for Bone and Mineral Research.
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The association of calcium and vitamin D with risk of colorectal adenomas.
Hartman, TJ, Albert, PS, Snyder, K, Slattery, ML, Caan, B, Paskett, E, Iber, F, Kikendall, JW, Marshall, J, Shike, M, et al
The Journal of nutrition. 2005;135(2):252-9
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Calcium and vitamin D may play a role in colorectal cancer incidence. One possible explanation is that they may act synergistically on a number of mechanisms to protect against recurrence of colonic adenomas. The aim of the study was to determine the effects of a high-fibre, high-fruit and vegetable, and low-fat diet on the recurrence of adenomatous polyps in the large bowel. For the present study, 1905 participants from the 2079 Polyp Prevention Trial participants who completed the full trial follow-up were evaluated. The participants’ diet was assessed at baseline and annually, and they also received full colonoscopies at baseline, their 1-year visit and at the end of the trial i.e. 4 years after randomization. Results show that there were no significant associations between any of the adenoma recurrence outcome variables and dietary or total calcium intake, consumption of low or high-fat dairy products or dietary vitamin D intake. However, total vitamin D intake was weakly inversely associated with adenoma recurrence. Calcium and vitamin D supplementation were also inversely associated with single and multiple adenoma recurrence. The study shows that calcium and vitamin D intake may provide weakly protective associations with the risk for recurrence of adenoma polyps.
Abstract
The Polyp Prevention Trial (PPT) was a multicenter randomized clinical trial designed to determine the effects of a high-fiber, high-fruit and vegetable, low-fat diet on the recurrence of adenomatous polyps in the large bowel. Detailed dietary intake and supplement use data were collected at baseline and at each of 4 annual study visits. Adenoma recurrence was ascertained by complete colonoscopy at baseline and after 1 and 4 y. Recurrence was found in 754 of the 1905 trial participants. We evaluated the association between calcium and vitamin D intake and adenomatous polyp recurrence after adjusting for intervention group, age, gender, nonsteroidal anti-inflammatory drug use, total energy intake, and the interaction of gender and intervention group. Vitamin D models were also adjusted for the location of the clinic site. Dietary variables were adjusted for total energy intake via the residual method. There were no overall significant associations between adenoma recurrence and dietary calcium intake [odds ratio (OR) for the 5th compared with the lowest quintile = 0.91; 95% CI = 0.67-1.23; P-trend = 0.68], total calcium intake (OR = 0.86; 95% CI = 0.62-1.18; P-trend = 0.20), or dietary vitamin D intake (OR = 0.93; 95% CI = 0.69-1.25; P-trend = 0.43) averaged over follow-up. Total vitamin D intake was weakly inversely associated with adenoma recurrence (OR = 0.84; 95% CI = 0.62-1.13; P-trend = 0.03). Supplemental calcium and vitamin D use during follow-up also were inversely associated with adenoma recurrence (OR for any compared with no use = 0.82; 95% CI = 0.68-0.99; and OR = 0.82; 95% CI = 0.68-0.99; for calcium and vitamin D, respectively). Slightly stronger associations were noted for the prevention of multiple recurrences. Our analyses did not suggest a significant effect modification between total calcium and total vitamin D intake (P = 0.14) on risk for adenoma recurrence. This trial cohort provides some evidence that calcium and vitamin D may be inversely associated with adenoma recurrence.