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1.
J Clin Endocrinol Metab ; 107(5): e1932-e1937, 2022 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-35022738

RESUMEN

CONTEXT: Supplementation with vitamin D has the potential to both reduce and increase risk of falling, and parathyroid hormone (PTH) may contribute to fall risk. OBJECTIVE: To assess the associations of intra-trial mean circulating levels of 25-hydroxyvitamin D [25(OH)D] and PTH on incident falls in healthy older adults. DESIGN: Observational within a clinical trial. SETTING: The Bone Metabolism Laboratory at the USDA Nutrition Center at Tufts University. PARTICIPANTS: 410 men and women age ≥65 years who participated in the 3-year Boston STOP IT trial to determine the effect of supplementation with 700 IU of vitamin D3 plus calcium on incident falls (secondary endpoint). Intra-trial exposures of 25(OH)D and PTH were calculated as the mean of biannual measures up to and including the first fall. MAIN OUTCOME MEASURES: Incidence of first fall. RESULTS: Intra-trial mean 25(OH)D was significantly associated with risk of falling in a U-shaped pattern; the range associated with minimal risk of falling was approximately 20 to 40 ng/mL. PTH was not significantly associated with risk of falling. CONCLUSIONS: The findings highlight the importance of maintaining the circulating 25(OH)D level between 20 and 40 ng/mL, the range that is also recommended for bone health. At PTH levels within the normal range, there was no detectible independent association of PTH with fall risk.


Asunto(s)
Deficiencia de Vitamina D , Vitamina D , Anciano , Boston/epidemiología , Femenino , Humanos , Masculino , Hormona Paratiroidea , Vitamina D/análogos & derivados
2.
Environ Pollut ; 248: 28-35, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30771745

RESUMEN

BACKGROUND: Heavy metal contamination is widespread in Bangladesh. Previous studies have observed lead increases blood pressure over time. However, the role of other metal contaminants and essential micronutrients, which could also adversely affect blood pressure or act as protective factors, is understudied. OBJECTIVES: We therefore evaluated the associations of lead, manganese, and selenium with blood and pulse pressure trajectories. METHODS: We prospectively followed placebo-assigned participants nested within a randomized trial for the prevention of arsenic-related skin cancer (n = 255). Blood lead, manganese, and selenium were measured at baseline; blood pressure was measured at baseline and at 3 biennial follow-up examinations. Mixed-effect linear regression models were used to estimate associations with average annual changes in systolic, diastolic, and pulse pressure. RESULTS: In models simultaneously adjusted for baseline blood lead, manganese, and selenium concentrations in addition to other potential confounders, lead was linearly associated with increases in systolic blood pressure, but not with diastolic blood pressure or pulse pressure. A non-linear association was observed for manganese, such that mid-range concentrations were associated with decreases in systolic, diastolic, and pulse pressure. Baseline selenium concentrations in the highest quartile were also associated with longitudinal decreases in both systolic and diastolic blood pressure, while null associations were observed with pulse pressure. In exploratory analyses, the combination of mid-range manganese and high selenium concentrations completely offset lead-associated increases in blood and pulse pressure. CONCLUSIONS: The results indicate a direct, linear association of lead exposure with systolic blood pressure, and manganese and selenium exposures within certain ranges may have a blood pressure-lowering effect in this population.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Manganeso/efectos adversos , Manganeso/sangre , Selenio/efectos adversos , Selenio/sangre , Adulto , Arsénico/análisis , Arsénico/toxicidad , Bangladesh , Estudios de Cohortes , Femenino , Humanos , Iones/análisis , Masculino , Metales Pesados/efectos adversos , Metales Pesados/sangre , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias Cutáneas/inducido químicamente
3.
Am J Clin Nutr ; 107(6): 1043-1053, 2018 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-29868916

RESUMEN

Background: Evidence from randomized controlled trials (RCTs) for the causal role of vitamin D on noncommunicable disease outcomes is inconclusive. Objective: The aim of this study was to investigate whether there are beneficial or harmful effects of cholecalciferol (vitamin D3) supplementation according to subgroups of remeasured serum 25-hydroxyvitamin D [25(OH)D] on cardiovascular and glucometabolic surrogate markers with the use of individual participant data (IPD) meta-analysis of RCTs. Design: Twelve RCTs (16 wk to 1 y of follow-up) were included. For standardization, 25(OH)D concentrations for all participants (n = 2994) at baseline and postintervention were re-measured in bio-banked serum samples with the use of a certified liquid chromatography-tandem mass spectrometry method traceable to a reference measurement procedure. IPD meta-analyses were performed according to subgroups of remeasured 25(OH)D. Main outcomes were blood pressure and glycated hemoglobin (HbA1c). Secondary outcomes were LDL, HDL, and total cholesterol and triglycerides; parathyroid hormone (PTH); fasting glucose, insulin, and C-peptide; and 2-h glucose. In secondary analyses, other potential effect modifiers were studied. Results: Remeasurement of 25(OH)D resulted in a lower mean 25(OH)D concentration in 10 of 12 RCTs. Vitamin D supplementation had no effect on the main outcomes of blood pressure and HbA1c. Supplementation resulted in 10-20% lower PTH concentrations, irrespective of the 25(OH)D subgroups. The subgroup analyses according to achieved 25(OH)D concentrations showed a significant decrease in LDL-cholesterol concentrations after vitamin D supplementation in 25(OH)D subgroups with <75, <100, and <125 nmol of -0.10 mmol/L (95% CI: -0.20, -0.00 mmol/L), -0.10 mmol/L (95% CI: -0.18, -0.02 mmol/L), and -0.07 mmol/L (95% CI: -0.14, -0.00 mmol/L), respectively. Patient features that modified the treatment effect could not be identified. Conclusions: For the main outcomes of blood pressure and HbA1c, the data support no benefit for vitamin D supplementation. For the secondary outcomes, in addition to its effect on PTH, we observed indications for a beneficial effect of vitamin D supplementation only on LDL cholesterol, which warrants further investigation. This trial was registered at www.clinicaltrials.gov as NCT02551835.


Asunto(s)
Calcifediol/farmacología , Enfermedades Cardiovasculares/sangre , Diabetes Mellitus Tipo 2/sangre , Adulto , Calcifediol/administración & dosificación , Calcio/administración & dosificación , Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus Tipo 2/prevención & control , Hemoglobina Glucada , Humanos , Hormona Paratiroidea/sangre
4.
Anal Chem ; 89(9): 4907-4913, 2017 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-28375002

RESUMEN

The National Institute of Standards and Technology (NIST) has developed Standard Reference Material (SRM) 972a Vitamin D Metabolites in Frozen Human Serum as a replacement for SRM 972, which is no longer available. SRM 972a was developed in collaboration with the National Institutes of Health's Office of Dietary Supplements. In contrast to the previous reference material, three of the four levels of SRM 972a are composed of unmodified human serum. This SRM has certified and reference values for the following 25-hydroxyvitamin D [25(OH)D] species: 25(OH)D2, 25(OH)D3, and 3-epi-25(OH)D3. The value assignment and certification process included three isotope-dilution mass spectrometry approaches, with measurements performed at NIST and at the Centers for Disease Control and Prevention (CDC). The value assignment methods employed have been modified from those utilized for the previous SRM, and all three approaches now incorporate chromatographic resolution of the stereoisomers, 25(OH)D3 and 3-epi-25(OH)D3.


Asunto(s)
25-Hidroxivitamina D 2/sangre , Calcifediol/sangre , Cromatografía Liquida/normas , Espectrometría de Masas/normas , 25-Hidroxivitamina D 2/normas , Calcifediol/química , Calcifediol/normas , Humanos , Estándares de Referencia , Valores de Referencia , Estereoisomerismo , Estados Unidos , United States Government Agencies
5.
Nutrients ; 8(9)2016 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-27589793

RESUMEN

Low vitamin D status is common in Europe. The major source of vitamin D in humans is ultraviolet B (UVB)-induced dermal synthesis of cholecalciferol, whereas food sources are believed to play a lesser role. Our objectives were to assess UVB availability (Jm(-2)) across several European locations ranging from 35° N to 69° N, and compare these UVB data with representative population serum 25-hydroxyvitamin D (25(OH)D) data from Ireland (51-54° N), Iceland (64° N) and Norway (69° N), as exemplars. Vitamin D-effective UVB availability was modelled for nine European countries/regions using a validated UV irradiance model. Standardized serum 25(OH)D data was accessed from the EC-funded ODIN project. The results showed that UVB availability decreased with increasing latitude (from 35° N to 69° N), while all locations exhibited significant seasonal variation in UVB. The UVB data suggested that the duration of vitamin D winters ranged from none (at 35° N) to eight months (at 69° N). The large seasonal fluctuations in serum 25(OH)D in Irish adults was much dampened in Norwegian and Icelandic adults, despite considerably lower UVB availability at these northern latitudes but with much higher vitamin D intakes. In conclusion, increasing the vitamin D intake can ameliorate the impact of low UVB availability on serum 25(OH)D status in Europe.


Asunto(s)
Disparidades en el Estado de Salud , Estaciones del Año , Luz Solar , Deficiencia de Vitamina D/epidemiología , Vitamina D/análogos & derivados , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Suplementos Dietéticos , Europa (Continente) , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Factores de Tiempo , Vitamina D/administración & dosificación , Vitamina D/sangre , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/diagnóstico , Deficiencia de Vitamina D/prevención & control , Adulto Joven
6.
Am J Clin Nutr ; 104(2): 454-61, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27385610

RESUMEN

BACKGROUND: Temporal trends in the US population's vitamin D status have been uncertain because of nonstandardized serum 25-hydroxyvitamin D [25(OH)D] measurements. OBJECTIVE: To accurately assess vitamin D status trends among those aged ≥12 y, we used data from the cross-sectional NHANESs. DESIGN: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring 25(OH)D (sum of 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3), calibrated to standard reference materials, was used to predict LC-MS/MS-equivalent concentrations from radioimmunoassay data (1988-2006 surveys; n = 38,700) and to measure LC-MS/MS concentrations (2007-2010 surveys; n = 12,446). Weighted arithmetic means and the prevalence of 25(OH)D above or below cutoff concentrations were calculated to evaluate long-term trends. RESULTS: Overall, mean predicted 25(OH)D showed no time trend from 1988 to 2006, but during 2007-2010 the mean measured 25(OH)D was 5-6 nmol/L higher. Those groups who showed the largest 25(OH)D increases (7-11 nmol/L) were older, female, non-Hispanic white, and vitamin D supplement users. During 1988-2010, the proportions of persons with 25(OH)D <40 nmol/L were 14-18% (overall), 46-60% (non-Hispanic blacks), 21-28% (Mexican Americans), and 6-10% (non-Hispanic whites). CONCLUSIONS: An accurate method for measuring 25(OH)D showed stable mean concentrations in the US population (1988-2006) and recent modest increases (2007-2010). Although it is unclear to what extent supplement usage compared with different laboratory methods explain the increases in 25(OH)D, the use of higher vitamin D supplement dosages coincided with the increase. Marked race-ethnic differences in 25(OH)D concentrations were apparent. These data provide the first standardized information about temporal trends in the vitamin D status of the US population.


Asunto(s)
Estado Nutricional , Deficiencia de Vitamina D/epidemiología , Vitamina D/sangre , Vitaminas/sangre , Adolescente , Adulto , Negro o Afroamericano , Anciano , Niño , Suplementos Dietéticos , Femenino , Hispánicos o Latinos , Humanos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Estado Nutricional/etnología , Prevalencia , Estados Unidos/epidemiología , Vitamina D/análogos & derivados , Vitamina D/uso terapéutico , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/prevención & control , Vitaminas/uso terapéutico , Población Blanca , Adulto Joven
7.
J Nutr ; 146(5): 1051-61, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27052537

RESUMEN

BACKGROUND: The 2007-2010 NHANES provides the first US nationally representative serum 25-hydroxyvitamin D [25(OH)D] concentrations measured by standardized liquid chromatography-tandem mass spectrometry. OBJECTIVE: We describe patterns for total 25(OH)D and individual metabolites in persons aged ≥1 y stratified by race-ethnicity and grouped by demographic, intake, physiologic, and lifestyle variables. METHODS: We measured 25-hydroxycholecalciferol [25(OH)D3], 25-hydroxyergocalciferol [25(OH)D2], and C3-epimer of 25(OH)D3 [C3-epi-25(OH)D3] in serum samples (n = 15,652) from the 2007-2010 cross-sectional NHANES [total 25(OH)D = 25(OH)D3 + 25(OH)D2]. RESULTS: Concentrations (median, detection rate) of 25(OH)D3 (63.6 nmol/L, 100%) and C3-epi-25(OH)D3 (3.40 nmol/L, 86%) were generally detectable; 25(OH)D2 was detectable in 19% of the population. Total 25(OH)D, 25(OH)D3, and C3-epi-25(OH)D3 displayed similar demographic patterns and were strongly correlated (Spearman's r > 0.70). Concentrations of 25(OH)D2 (90th percentile) were much higher in persons aged ≥60 y (17.3 nmol/L) than in younger age groups (≤4.88 nmol/L). We noted significant race-ethnicity differences in mean total 25(OH)D [non-Hispanic blacks (NHBs), Hispanics, and non-Hispanic whites (NHWs): 46.6, 57.2, and 75.2 nmol/L, respectively] and in the prevalence of total 25(OH)D <30 nmol/L overall (24% of NHBs, 6.4% of Hispanics, and 2.3% of NHWs) as well as stratified by season (winter months: 30% of NHBs, 7.5% of Hispanics, and 3.8% of NHWs; summer months: 17% of NHBs, 4.4% of Hispanics, and 1.6% of NHWs). Persons with higher vitamin D intakes (diet, supplements, or both) and those examined during May-October had significantly higher total 25(OH)D. Significant race-ethnicity interactions in a multiple linear regression model confirmed the necessity of providing race-ethnicity-specific estimates of total 25(OH)D. CONCLUSIONS: Race-ethnicity differences in the prevalence of low total 25(OH)D remained strong even after adjustment for season to account for the NHANES design imbalance between season, latitude, and race-ethnicity. The strong correlation between C3-epi-25(OH)D3 and 25(OH)D3 may be because the epimer is a metabolite of 25(OH)D3. The presence of 25(OH)D2 mainly in older persons is likely a result of high-dose prescription vitamin D2.


Asunto(s)
Negro o Afroamericano , Hispánicos o Latinos , Deficiencia de Vitamina D/epidemiología , Vitamina D/sangre , Población Blanca , 25-Hidroxivitamina D 2/sangre , Adolescente , Adulto , Factores de Edad , Anciano , Calcifediol/sangre , Niño , Preescolar , Cromatografía Líquida de Alta Presión/métodos , Dieta , Suplementos Dietéticos , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Estaciones del Año , Espectrometría de Masas en Tándem/métodos , Estados Unidos/epidemiología , Vitamina D/análogos & derivados , Deficiencia de Vitamina D/sangre , Vitaminas/sangre , Adulto Joven
8.
Clin Chem ; 61(4): 636-45, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25710460

RESUMEN

BACKGROUND: 24,25-Dihydroxyvitamin D [24,25(OH)2D] in serum may be both a nuisance and nutritionally valuable. METHODS: We investigated the impact of 24,25(OH)2D3 on the performance of commercially available immunoassays for serum total 25-hydroxyvitamin D [25(OH)D] using (a) serum from a nationally representative sample of adults, (b) serum from a spiking experiment, and (c) data from the UK Vitamin D External Quality Assurance Scheme (DEQAS). We also investigated the utility of the serum ratio of 24,25(OH)2D3 to 25(OH)D as an index of inactivation and of response to vitamin D supplementation using randomized controlled trial (RCT) data. Measurement of 24,25(OH)2D in sera by a LC-MS/MS method allowed for an investigation of its impact on immunoassay-derived serum 25(OH)D values as well as its clinical utility. We report data from a nationally representative sample of adults, a recent vitamin D RCT in older adults, and DEQAS. RESULTS: 24,25(OH)2D3 contributed to the positive bias observed in some immunoassays relative to LC-MS/MS-derived estimates for total 25(OH)D. A spiking experiment showed that the degree of cross-reactivity with 24,25(OH)2D was high and may underpin this positive bias. Adjustment for 24,25(OH)2D3 concentration brought estimates closer to true values. Data from the vitamin D RCT showed that the ratio of 24,25(OH)2D3 to 25(OH)D was associated with serum 25(OH)D3 and with response of serum 25(OH)D to vitamin D supplementation. CONCLUSIONS: Our findings highlight that the effect of 24,25(OH)2D3 in serum is a double-edged sword-an interferent for some immunoassays, yet potentially informative of nutritional status.


Asunto(s)
24,25-Dihidroxivitamina D 3/sangre , Técnicas para Inmunoenzimas/normas , Vitamina D/análogos & derivados , Cromatografía Liquida , Reacciones Cruzadas , Suplementos Dietéticos , Método Doble Ciego , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Espectrometría de Masas en Tándem , Vitamina D/sangre
9.
J Obes Weight Loss Ther ; 3(4): 181, 2013 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-25632374

RESUMEN

The impact of 25-hydroxyvitamin D (25[OH]D) supplementation on weight change remains controversial. The objective of this study was to summarize the effects of 25[OH]D supplementation (cholecalciferol or ergocalciferol) on BMI change through a meta-analysis of published clinical trials. We completed a systematic review of English articles, using MEDLINE (Ovid, Pubmed) from January 1, 1998 through January 1, 2013. The articles selected focused on 25[OH]D supplementation and body mass index (BMI) in randomized controlled trials (RCT's). The association between 25[OH]D and mean BMI change was estimated utilizing a random effects model. A total of 30 studies were reviewed and 9 were included in the meta-analysis. Total participants included 1651 adults (82.6% women and mean age 47.9 years) and mean follow-up ranged between 6 to 196 weeks and mean daily 25[OH]D dose ranged from 200 IU to 1,110 IU. Five of the 9 studies included calcium supplementation in both groups. Average baseline BMI was 30.7 and 30.4 kg/m2 in the intervention and control groups, respectively. Five studies suggested a beneficial effect for 25[OH]D supplementation for BMI change whereas 3 studies showed no effect of 25[OH]D supplementation on BMI change, and one showed a non-perceptible change. Meta-analysis of BMI values at end of trial showed no statistically significant difference in BMI change by use of 25[OH]D supplementation. Based on existing published trials, oral 25[OH]D supplementation does not significantly impact BMI change.

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