Variation In Serum 25-hydroxyvitamin Research Articles

Possible Association of Female-Pattern Hair Loss with Alteration in Serum 25-Hydroxyvitamin D Levels

Background and Aim: Most women who experience diffuse hair loss suffer from female-pattern hair loss (FPHL). Several mechanisms other than androgen have been suggested as contributing to the process. Serum 25-hydroxy vitamin D [25-(OH) D] has been associated with other hair disorders. The present study aimed to assess the female-pattern hair loss possible association with variation in serum 25-hydroxyvitamin D levels. Patients and Methods: This case-control study was conducted on 72 FPHL diagnosed female patients attending dermatology department of Tertiary Care Hospitals in Jamshoro and Karachi from November 2021 to October 2022. Females aged 18-40 years with skin prototypes III and IV were enrolled. About 72 healthy females were considered as control group. Study protocol was approved by the institutional research and ethical committee. Careful history, socioeconomic status, FPHL family history, menstrual history, and drug intake were recorded from cases and control. Patients were classified as having stage I, II, or III FPHL based on a clinical evaluation of the pattern of hair loss using Ludwig's scale. 25-OHD levels over a period of 4 months were measured to minimize seasonal bias. Females with 25-OHD levels <20 ng/ml were deficient, insufficient 21–29 ng/ml, sufficient >30 ng/ml, and intoxication >150 ng/ml. SPSS version 26 was used for data analysis. Results: The overall mean age was 28.6±2.4 years. Age-wise distribution of patients were as follows: 9 (12.5%) in 18-25 years, 24 (33.3%) in 26-30 years, 21 (29.2%) in 31-35 years, and 18 (25%) 36-40 years. Serum 25-(OH) D levels in FPHL patients were significantly lower (15.4 ± 8.25 ng/ml) than in controls (46.42 ± 19.92 ng/ml). The mean vitamin D level did not differ significantly between patients with and without family history (14.46 ± 8.62 and 13.9 ± 8.24 ng/ml, respectively. The mean vitamin D level differed significantly between the three Ludwig's degrees (13.15 ± 8.49, 14.23 ± 6.74, and 24.9 ± 6.42 ng/ml, respectively): between degrees I and III, as well as between degrees II and III. Conclusion: The present study showed that hair loss varied significantly across all age groups. Premenopausal women with vitamin D deficiency have higher rates of hair loss, which is most profound in the age groups 26-30, followed by 25-30. Furthermore, changes in serum 25-(OH) D levels, whether deficient or sufficient, may play a role in the etiology of FPHL. Keywords: Female Pattern Hair Loss (FPHL), Vitamin D, Serum 25-hydroxy vitamin D

Longitudinal Stability of Vitamin D Status and Its Association With Bone Mineral Density in Middle-aged Australians.

The skeletal effects of vitamin D remain controversial and it is uncertain whether variation in serum 25-hydroxyvitamin D (25OHD) levels over time influences bone mineral density (BMD). We evaluated longitudinal stability of serum 25OHD and associations with changes in BMD in participants aged 46-70 years at baseline. We studied 3698 Busselton Healthy Ageing Study participants (2040 female) with serum 25OHD and dual-energy x-ray absorptiometry (DXA) BMD assessments at baseline and at ∼6 years follow-up. Restricted cubic splines were used to evaluate associations between changes in 25OHD and BMD. Mean season-corrected serum 25OHD was 81.3 ± 22.7 and 78.8 ± 23.1 nmol/L at baseline and 6 years, respectively, and showed moderate correlation (intraclass correlation coefficient: 0.724). Significant predictors of change in 25OHD concentration (Δ25OHD) included baseline 25OHD, change in body mass index and vitamin D supplementation at follow-up. Greater decline in serum 25OHD over time was associated with significantly greater reduction in BMD at total hip and femoral neck, but the magnitude of the differences was small (estimated differences 0.004 g/cm2 and 0.005-0.007 g/cm2, respectively, for lowest quartile of Δ25OHD compared with higher quartiles, adjusted for sex, baseline BMD, 25OHD, and demographics). No significant associations between Δ25OHD and lumbar spine BMD were observed. Increase in 25OHD levels was not associated with change in BMD. In this predominantly vitamin D-replete middle-aged cohort, serum 25OHD showed moderate longitudinal stability. Declining serum 25OHD over time was associated with greater reduction in BMD at the total hip and femoral neck.

A Narrative Review of the Evidence for Variations in Serum 25-Hydroxyvitamin D Concentration Thresholds for Optimal Health.

Vitamin D3 has many important health benefits. Unfortunately, these benefits are not widely known among health care personnel and the general public. As a result, most of the world’s population has serum 25-hydroxyvitamin D (25(OH)D) concentrations far below optimal values. This narrative review examines the evidence for the major causes of death including cardiovascular disease, hypertension, cancer, type 2 diabetes mellitus, and COVID-19 with regard to sub-optimal 25(OH)D concentrations. Evidence for the beneficial effects comes from a variety of approaches including ecological and observational studies, studies of mechanisms, and Mendelian randomization studies. Although randomized controlled trials (RCTs) are generally considered the strongest form of evidence for pharmaceutical drugs, the study designs and the conduct of RCTs performed for vitamin D have mostly been flawed for the following reasons: they have been based on vitamin D dose rather than on baseline and achieved 25(OH)D concentrations; they have involved participants with 25(OH)D concentrations above the population mean; they have given low vitamin D doses; and they have permitted other sources of vitamin D. Thus, the strongest evidence generally comes from the other types of studies. The general finding is that optimal 25(OH)D concentrations to support health and wellbeing are above 30 ng/mL (75 nmol/L) for cardiovascular disease and all-cause mortality rate, whereas the thresholds for several other outcomes appear to range up to 40 or 50 ng/mL. The most efficient way to achieve these concentrations is through vitamin D supplementation. Although additional studies are warranted, raising serum 25(OH)D concentrations to optimal concentrations will result in a significant reduction in preventable illness and death.

Vitamin D Levels in Patients with and without Acne and Its Relation to Acne Severity: A Case-Control Study.

BackgroundVitamin D plays a significant role in the function of the immune system and it influences many dermatological diseases such as psoriasis and atopic dermatitis. The prevalence of vitamin D deficiency is growing globally, with around 30–50% of people are known to have low levels of vitamin D. Acne vulgaris is a common inflammatory disorder of the pilosebaceous unit. Studies about the role of vitamin D in the pathogenesis of acne vulgaris have shown conflicting and nonconclusive results. Thus, the precise purpose of vitamin D has not yet been established.ObjectiveFirst, to evaluate serum levels of vitamin D through a representative sample of patients with acne vulgaris and compare it with matched healthy controls. Second, to investigate if there is a relation between serum vitamin D level and the severity of acne vulgaris.Materials and MethodsThis cross-sectional study included 68 patients with acne vulgaris and 50 matched healthy controls. Serum 25-hydroxyvitamin D [25 (OH) D] levels were measured for both patients and healthy controls.ResultsThe study yielded lower levels of serum 25-hydroxyvitamin D in patients with acne vulgaris than its level in healthy controls. This is statistically significant with P-value = 0.003. Regarding age, gender, and sun exposure, there is no significant variation in serum 25-hydroxyvitamin D level. Also, no significant difference between the severity of acne and serum 25-hydroxyvitamin D levels.ConclusionThis study has shown clearly that vitamin D deficiency is more frequent in patients with acne with P-value = 0.003. However, no significant association between the serum level of 25-hydroxyvitamin D [25 (OH) D] and the severity of acne vulgaris. Further clinical trials on a larger scale are needed to address the importance of vitamin D in acne vulgaris. Specifically, determining whether treatment of acne with both topical vitamin D analogs and vitamin D supplementation is of significant effect.

Seasonal Variation in Serum 25-hydroxy Vitamin D and its Association with Clinical Morbidity in Healthy Infants from Northern India

To evaluate the seasonal change in serum 25-hydroxyvitamin D (25-OHD) level in healthy infants and to relate it to common childhood morbidities. 72 healthy breastfed infants residing in Delhi were enrolled at the end of summer and followed till the end of winter [mean (SD) duration 200 (10) d]. Serum 25-OHD was estimated at baseline and follow-up. Infants were monitored for common childhood diseases. Mean (SD) serum 25-OHD level was lower at the end of winter (20.7 (8.02) ng/mL) than summer (22.9 (8.70) ng/mL) [mean difference (95% CI) -2.14 ng/mL (-3.36, -1.06), P<0.001). The seasonal distribution of children according to vitamin D status in summer and winter - Deficient (15.3%, 12.5%), Insufficient (19.4%, 30.6%) and Sufficient (65.3%, 56.9%), respectively was comparable P=0.17). The morbidity profile remained unaffected by change in vitamin D status from summer to winter. Seasonal changes in vitamin D levels do not have significant clinical effect or effect on overall vitamin D status in apparently healthy infants from North India. This may have implications for results of population surveys for vitamin D status, irrespective of the season when they are conducted.

The Association of a Breast Cancer Diagnosis With Serum 25-Hydroxyvitamin D Concentration Over Time.

Prospective and retrospective studies of vitamin D levels and breast cancer have produced discrepant results. This may be due to variations in serum 25-hydroxyvitamin D (25(OH)D) concentrations over time, including systematic changes after breast cancer diagnosis. We measured total serum 25(OH)D levels in participants from the Sister Study, a US cohort study of sisters of breast cancer patients, who provided samples at baseline (2003-2009) and 4-10 years later (2013-2015). This included 827 women with an intervening breast cancer and 771 women without one. Although 25(OH)D levels were modestly correlated over time (R = 0.42), 25(OH)D concentrations increased in both groups, with larger increases among cases (averaging 31.6 ng/mL at baseline and 43.5 ng/mL at follow-up) than among controls (32.3 ng/mL at baseline, 40.4 ng/mL at follow-up). Consequently, the estimated association between 25(OH)D and breast cancer depended on whether baseline measurements (per 10-ng/mL increase, odds ratio = 0.87, 95% confidence interval: 0.78, 0.98) or measurements from the second blood draw (per 10-ng/mL increase, odds ratio = 1.17, 95% confidence interval: 1.08, 1.26) were used. Concentrations were related to regular use (≥4 times/week) of vitamin D supplements, which became more common over time; increases in regular use were greater in cases (from 56% to 84%) than in controls (from 56% to 77%). Our results do not explain previously observed differences between retrospective and prospective studies, but they do demonstrate how reverse causation and temporal trends in exposure can distort inference.

Longitudinal changes in serum 25-hydroxyvitamin D in the Dallas Heart Study.

While the prevalence of vitamin D deficiency is well described in various populations, limited data are available regarding longitudinal variation in serum 25-hydroxyvitamin D concentrations. To evaluate the temporal trends in serum 25(OH)D, prevalence of vitamin D deficiency and factors influencing these trends. Adults enrolled in the Dallas Heart Study, a longitudinal, probability-based, multiethnic, population study in Dallas, Texas, USA. Prevalence of vitamin D deficiency and predictors of change in serum 25(OH)D. A total of 2045 participants had serum 25(OH)D measured on two occasions (2000-2002 and 2007-2009) at a median interval of 7years. Serum 25(OH)D decreased (42.7-39.4nmol/L, P<.001) and the prevalence of vitamin D deficiency [25(OH)D <50nmol/L] increased significantly (60.6%-66.4%, P<.0001) despite vitamin D supplementation increasing over the interval (7.2%-23.0%; P<.0001). In a multivariable model adjusting for sex, race, BMI, age, season of blood draw, smoking and exercise, a greater decline in serum 25(OH)D was noted in men compared with women (-8.0 vs -3.5nmol/L, P<.0001), in participants of Hispanic ethnicity vs White and Black ethnicity (P<.0001), in nonobese vs obese participants (-7.2 vs -4.0nmol/L, P=.005) and in nonusers vs users of vitamin D supplements (-5.7 vs -1.7nmol/L, P=.032). Despite increased vitamin D supplementation, serum 25(OH)D decreased in an ethnically diverse cohort of Dallas County residents between 2000-2002 and 2007-2009. Features most predictive of a decline in serum 25(OH)D include male sex, Hispanic ethnicity and weight gain.

Seasonal changes in serum calcium, PTH and vitamin D levels in patients with primary hyperparathyroidism

BackgroundSeasonal variations of 25-hydroxyvitamin D, PTH and calcium levels are not well characterized in primary hyperparathyroidism (PHPT). Our objectives were to characterize seasonal changes in these parameters in PHPT patients, and to assess whether these seasonal changes affect clinical decision making. MethodsThis is a retrospective study based on the electronic medical records of Clalit Health service in the south of Israel between 2000 and 2012. Patients 18years and older with PHPT (PTH>upper limit of norm (ULN) and serum calcium>10.5mg%) were included. Patients with renal failure or on Thiazide diuretics were excluded. All serum levels of calcium, PTH and 25-hydroxyvitamin D were collected and then stratified according to season. Results792 patients were classified as PHPT (72.2% female) and had a total of 2659 PTH tests, 1395 25-hydroxyvitamin D tests and 7426 calcium test. Fifty six percent of 25-hydroxyvitamin D levels were <50nmol/L. Seasonality was demonstrated in all three parameters: mean 25-hydroxyvitamin D was 13% higher in the summer compared to the winter (P<0.001), median PTH values showed opposite trend with a fall of about 8.4% in summer compared to winter (P<0.001). Calcium levels were higher during the autumn with a rise of about 0.2mg/dL in the mean calcium levels compared to spring and summer (P<0.001). The odds ratio of calcium level above 11.5mg/dL is highest in the autumn (OR=1.275, P=0.018). ConclusionWe show seasonal variation in serum 25-hydroxyvitamin D, PTH, and calcium levels in patients with PHPT. These seasonal variations cause transition to pathological values that may influence diagnosis and treatment of PHPT patients.

25-Hydroxyvitamin D3 Levels, BsmI Polymorphism and Insulin Resistance in Brazilian Amazonian Children.

Vitamin D is associated with a wide range of other functions beyond bone development. We evaluated the factors associated with 25-hydroxyvitamin D levels in 974 children aged ≤10 years and the impact of BsmI polymorphism of the vitamin D receptor (VDR) gene (rs1544410) on metabolic parameters in a subsample (n: 430) with a follow-up 2 years later from the initial population-based cross-sectional study. Multiple linear regression models were used in the analyses. The prevalence (95% CI) of vitamin D deficiency, insufficiency and sufficiency of children was 11.1% (9.2–13.2), 21.8% (19.2–24.5) and 67.2% (64.1–70.1), respectively. Overall, 23% of the variation in serum 25-hydroxyvitamin D concentrations was accounted for by BsmI polymorphism β = −0.053 (95% CI) (−0.100, −0.006), maternal schooling (≥9 years) β = 0.100 (0.039, 0.161), serum vitamin E β = 0.478 (0.381, 0.574), total cholesterol concentration β = 0.232 (0.072, 0.393) and serum folate β = 0.064 (0.013, 0.115). BsmI polymorphism was positively associated with HOMA-IR β = 0.122 (0.002, 0.243) and fasting glucose concentration β = 1.696 (0.259, 3.133). In conclusion, variables related to socioeconomic level, the presence of the allele risk for BsmI and other nutrient concentrations were associated with serum 25-hydroxyvitamin D concentrations. Our results suggest that BsmI polymorphism is correlated with metabolic outcomes.

Seasonal variations in serum 25-hydroxy vitamin D levels in a Swedish cohort.

To study seasonal inter-individual and intra-individual variations in serum 25-hydroxy vitamin D (25(OH)D) and to explore parameters associated with 25(OH)D in a healthy Swedish adult population. 540 blood donors (60 % men; mean age 41 ± 13 years) and 75 thrombocyte donors (92 % men, aged 46 ± 11 years) were included. Serum was collected during 12 months and analyzed for 25(OH)D and parathyroid hormone (S-iPTH). The blood donors answered questionnaires concerning vitamin D supplements, smoking, physical activity, sunbed use and sun holidays. Repeated serum samples were collected from the thrombocyte donors to study the intra-individual variations in S-25(OH)D. S-25(OH)D varied greatly over the year correlating with the intensity of the UV-B irradiation (r S = 0.326; p < 0.001). During January–March, a S-25(OH)D level below the thresholds of 50 and 75 nmol/L was observed in 58 and 88 %, respectively, and during July–September in 11 and 50 % (p < 0.001). S-25(OH)D was negatively correlated with body mass index and S-iPTH, but was significantly higher in holiday makers in sunny destinations, sunbed users, non-smokers, and in the physically active. The intra-individual analyses showed a mean increase in S-25(OH)D by 8 nmol/L/month between April and August. Approximately 75 % had serum 25(OH)D values <75 nmol/L during 75 % of the year and 50 % had serum 25(OH)D <50 nmol/L during 50 % of the year. Serum 25(OH)D was strongly associated with parameters related to sun exposure, but only weakly with intake of vitamin D supplements.

Ethnic aspects of vitamin D deficiency.

Vitamin D deficiency has been linked to bone fragility in children and adults, and to an increased risk of chronic diseases. The main sources of vitamin D are the diet and cutaneous synthesis, the latter being the most important one, since foods are relatively poor in vitamin D. The main factors influencing this endogenous production are the seasons, the time of day, latitude and skin phototype. Due to the contribution of sun exposure in maintaining vitamin D levels, it would be expected that this deficiency would be more prevalent in countries at a high latitude; it has been shown, however, that hypovitaminosis D is commonly found in tropical regions such as Brazil. In high latitude regions in which extreme skin phototypes have been compared, the prevalence of vitamin D deficiency is more common in people with originally darker skin who have a natural barrier to the already lower UV irradiation penetrating the skin. In Brazil, particularly in the areas where sun rays are more abundant, the difference in sunlight exposure between subjects showed no significant variation in serum 25-hydroxyvitamin D (25OHD).

Serum 25‐hydroxy vitamin D is associated with blood total cholesterol and diastolic blood pressure in a young multi‐ethnic group living in South Florida (1041.15)

Objective: The aim of this study was to investigate the relationship between serum 25‐hydroxy vitamin D, total cholesterol and blood pressure (BP) among young multi‐ethnic participants living in South Florida.Methods: This cross‐sectional study included 80 young adults, males (n=42) and females (n=38), ages 18‐36 years recruited from Florida International University campus. Serum 25‐hydroxy vitamin D and TC were measured by ELISA method. Systolic and diastolic BPs were measured by an automated monitor. Weekly total sun exposure and daily vitamin D intake were calculated from validated sun exposure and food frequency questionnaires respectively. A multi‐linear regression model was run, adjusting for age, gender, body mass index, systolic BP, daily vitamin D intake, total weekly sun exposure and tobacco use.Results: Total cholesterol (P= 0.020) and diastolic blood pressure (P= 0.025) were negatively associated with serum 25‐hydroxy vitamin D. This association remained significant after controlling for covariates (B= ‐0.074, P=.045 for total cholesterol, B= ‐0.421, P= ‐0.018 for diastolic blood pressure). The model explained 18.4% of the variation in serum 25‐hydroxy vitamin D.Conclusion: The results of this study suggest that high total blood cholesterol and diastolic blood pressure may be associated to low serum 25‐hydroxy vitamin D level. Interventions are needed to confirm these results.Grant Funding Source: Supported by NIH/NIDDK sponsored grant.

Longitudinal changes and seasonal variations in serum 25-hydroxyvitamin D levels in different age groups: results of the Longitudinal Aging Study Amsterdam

Vitamin D levels remained fairly stable during ageing with increasing levels in persons aged 55-65years old and decreasing levels in persons aged 65-88years old. The seasonal variation was larger than the longitudinal change. Our findings implicate that vitamin D supplementation becomes more important in older age groups and during wintertime. Longitudinal changes in serum 25-hydroxyvitamin D (25-OHD) levels during aging have not been studied extensively. Two studies showed increasing serum 25-OHD levels. One of these studies suggested that there might be decreasing levels in persons aged 65years and older. The objectives of the current study are the following: (1) to examine longitudinal changes in serum 25-OHD levels in different age groups and (2) to describe the seasonal variation in different age groups. Data of the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study, were used. Two different cohorts were included: (1) younger cohort: aged 55-65years old at baseline, n = 738, follow-up of 6years and (2) older cohort: aged 65-88years old at baseline, n = 1,320, follow-up of 13years. At baseline, average levels were 56.5nmol/L in the younger cohort and 51.1nmol/L in the older cohort. In the younger cohort, a longitudinal increase in the mean serum 25-OHD levels of 4nmol/L in 6years was observed; in the older cohort, a longitudinal decrease in the mean serum 25-OHD levels of 4nmol/L in 13years was observed. The seasonal variation was ±12nmol/L in the younger cohort and ±7nmol/L in the older cohort. Long-term serum 25-OHD levels remained fairly stable during aging with slightly increasing levels in persons aged 55-65years old and slightly decreasing levels in persons aged 65-88years old. On average, the seasonal variation was larger than the longitudinal change. Our findings implicate that vitamin D supplementation becomes more important in older age groups and during wintertime.

Vitamin D Deficiency in Children with a Chronic Illness–Seasonal and Age-Related Variations in Serum 25-hydroxy Vitamin D Concentrations

IntroductionChildren and adolescents with a chronic illness have potential risk factors for vitamin D deficiency. An optimal vitamin D status might have multiple health effects. This study evaluated vitamin D status and its association with age, gender, and season in a large cohort of chronically ill Finnish patients at a tertiary pediatric outpatient clinic. A cross-sectional register-based study was carried out, involving altogether 1351 children (51% boys, age range 0.2–18 years), who visited the outpatient clinic during 2007–2010 and had their vitamin D status (S-25-OHD) determined. A post-doc analysis was conducted to identify predisposing and preventing factors for vitamin D deficiency.ResultsAlmost half (47%) of the S-25-OHD values were consistent with subnormal vitamin D status (S-25-OHD <50 nmol/L) while only 12% were >80 nmol/L. Age and season were the most important determinants for S-25-OHD concentration. Mean S-25-OHD concentration differed between age groups (Kruskal-Wallis; p<0.001), adolescents being at highest risk for vitamin D insufficiency. Young age and vitamin D supplementation were preventive factors for deficiency, while non-Finnish ethnic background was a predisposing factor. S-25-OHD showed significant seasonal variation in children older than 6 years. In the whole cohort, S-25-OHD was on average 13 nmol/L higher in summer than in winter, and the prevalence of vitamin D deficiency ( = S-25-OHD <37.5 nmol/l) varied from 11% in summer to 29% in winter.ConclusionsThe finding that almost half of the studied Finnish children with a chronic illness had suboptimal vitamin D status is alarming. Inferior vitamin D status was noted in adolescents compared with younger children, suggesting that imbalance between intake and requirement evolves with age. Although less common during summer, subnormal vitamin D status was still observed in 28% of those evaluated in summer. Clinicians should identify individuals at risk and actively recommend vitamin D supplementation.

Vitamin D Status of Exclusively Breastfed 4-Month-Old Infants Supplemented During Different Seasons

To examine the vitamin D status of 4-month-old exclusively breastfed infants supplemented with 400 IU daily of vitamin D and to determine whether there was any seasonal variation in serum 25-hydroxyvitamin D (25(OH)D) levels of infants. In this cross-sectional study, serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone, and 25(OH)D levels of 143 exclusively breastfed 4-month-old infants supplemented daily with 400 IU of vitamin D were measured in a temperate latitude, Izmir, Turkey, between May 2008 and April 2009. A questionnaire on demographic characteristics of infants and mothers, vitamin D supplementation of infants after birth, mothers' multivitamin supplementation, dressing habits, and consumption of dairy products during pregnancy was used. Vitamin D deficiency (≤ 50 nmol/L) and insufficiency (51-74 nmol/L) were determined in 40 (28%) and 55 (38.5%) infants, respectively. During winter days, serum 25(OH)D levels were <20 ng/mL in 45.4% of infants and <10 ng/mL in 10.6% of infants. Season of blood sampling, compliance of vitamin D supplementation, maternal education level, and consumption of dairy products were highly predictive of serum 25(OH)D levels in multiple linear regression analysis (P < .05). The use of the Pearson correlation test found a statistically significant negative correlation between 25(OH)D and parathyroid hormone levels (r = -0.419, P < .001). Despite supplementation with 400 IU of vitamin D daily, the rate of vitamin D deficiency was worryingly high in 4-month-old exclusively breastfed infants living in Izmir, Turkey. So, additional studies are needed to clarify optimal amount of vitamin D supplementation to the infants, especially during winter days.

High prevalence of winter 25-hydroxyvitamin D deficiency despite supplementation according to guidelines for hemodialysis patients

There are seasonal variations in serum 25-hydroxyvitamin D (25OHD) levels related to sun exposure. Recent guidelines suggest a target serum 25OHD level >30ng/ml in chronic kidney disease patients. However, vitamin D supplementation dosing and monitoring regimens are not well established in hemodialysis patients. The aim of this study was to assess the interplay between season and 25OHD supplementation according to guidelines on 25OHD levels in hemodialysis patients. We retrospectively reviewed data collected prospectively over 12months in 32 stable hemodialysis patients receiving 25OHD supplements (mean dose 30,600IU/month) under routine clinical care following the Spanish Society of Nephrology guidelines. Higher serum 25OHD was observed during the summer, peaking in June and August. Despite a trend towards a higher 25OHD dose in winter the prevalence of 25OHD deficiency was still >40% in winter. Furthermore, despite a higher dose of calcium-based phosphate binders, there was a trend toward lower serum calcium in winter. Season, together with residual diuresis and dry weight, was a significant independent contributor to a multivariate lineal regression model that explained 25% of serum 25OHD variability, while a 25OHD dose did not contribute significantly in this 25OHD-supplemented population. Winter vitamin D deficiency is prevalent in hemodialysis patients despite supplementation with 25OHD according to clinical guidelines. More intensive monitoring or pre-emptive winter dose increases should be evaluated to achieve guideline targets.

Hypovitaminosis D in Adults with Inflammatory Bowel Disease: Potential Role of Ethnicity

Although vitamin D deficiency occurs in inflammatory bowel disease (IBD), it is currently unclear to what extent ethnicity affects vitamin D levels. Our aim was therefore to determine the ethnic variation in serum 25-hydroxyvitamin D status and its association with disease severity in adults with IBD. We conducted a prospective cohort study in ambulatory care IBD patients. Clinical disease severity was assessed through validated questionnaires. Serum 25-hydroxyvitamin D levels were used for vitamin D status. C-reactive protein (CRP), ferritin and hemoglobin (Hgb) levels were correlated with serum 25-hydroxyvitamin D levels. Sixty ulcerative colitis (UC) and forty Crohn's disease (CD) patients were enrolled comprising 65 % Caucasians and 29 % South Asians. However, South Asians had consistently lower average serum 25-hydroxyvitamin D levels (All 44.8 ± 18.1 nmol/L, UC 48.2 ± 18.3 nmol/L, CD 24.3 ± 13.3 nmol/L). Hypovitaminosis D was found in 39 % of All, 36.7 % of UC and 42.5 % of CD patients. A significantly higher proportion of South Asians were vitamin D deficient when compared to Caucasians in All and CD groups (58.6 % vs. 30.8 %, p = 0.01 and 85.7 % vs. 32.3 %, p < 0.01, respectively). A significantly higher percentage of South Asians had hypovitaminosis D when compared to Caucasians. Disease severity trended towards an inverse relationship with vitamin D status in all South Asian and Caucasian CD patients, although most patients in this study had only mild to moderate disease. We suggest that vitamin D supplementation should be considered in all adult IBD patients.

Variations in Serum 25-Hydroxyvitamin D during Acute Pancreatitis: An Exploratory Longitudinal Study

Objectives. We tested the hypothesis that 25-hydroxyvitamin D3 (25OHD) changes during acute inflammation in humans. Methods. Patients with first episode of acute pancreatitis were included. Blood samples were acquired on admission and on days 1, 2, and 14. Results. In total, 73 patients (35 males, median age 59) entered the study. On admission, the distribution of 25-OHD levels was as follows: severely deficient (<13 nmol/L) 23%; deficient (13–25 nmol/L) 20%; insufficient (26–50 nmol/L) 40%; and normal (<50 nmol/L) 17%. There was a significant fall and linear trend in 25OHD, albumin, and hemoglobin from day 0 to day 2. From day 0 to day 2 the drop in 25OHD was 3.1 nmol/L (95% CI 0.59–5.63). The changes from day 0 to day 2 in 25OHD were associated with changes in C-reactive protein (p = 0.02) but not with leukocyte or monocyte count. Conclusions. The 25OHD levels dropped during the first 2 days of acute pancreatitis beyond what was expected based on 25OHD half-life. This study supports our hypothesis that an acute inflammatory condition utilizes 25OHD, but other mechanisms could interfere.

Multiple sclerosis prevalence in Ireland: relationship to vitamin D status and HLA genotype

BackgroundThe relationship between prevalence of multiple sclerosis (MS) and latitude may be due to both genetic and environmental factors. The hypothesis that, in Ireland, MS prevalence is increasing and that...

Abstract 3770: Long-term variation in serum 25-hydroxyvitamin D concentration among participants in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial

Abstract Molecular epidemiologic studies of vitamin D and risk of cancer and other health outcomes usually involve a single measurement of the biomarker 25-hydroxyvitamin D [25(OH)D] in serum or plasma. However, the extent to which 25(OH)D concentration at a single time point is representative of an individual's long-term vitamin D status is unclear. To address this question, we evaluated within-person variability in 25(OH)D concentration across serum samples collected at three time points over a five year period among 29 participants in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Serial blood samples in the PLCO Cancer Screening Trial were obtained from each subject at the same time of year for each of the three collection events. This sample collection protocol provided a unique opportunity to evaluate within-person temporal variability beyond seasonal effects, which have been well-characterized in previous studies. The within-person coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated using variance components estimated from random effects models. Spearman rank correlation coefficients were calculated to evaluate agreement between measurements at different collection times (baseline, +1 year, +5 years). The within-subject CV was 14.9% [95% confidence interval (CI) 12.4%-18.1%] and the ICC was 0.71 (95% CI 0.63-0.88). Spearman rank correlation coefficients comparing baseline to +1 year, +1 year to +5 years, baseline to +5 years, and the average of baseline and +1 year to +5 years were 0.65 (0.37-0.82), 0.61 (0.29-0.81), 0.53 (0.17-0.77), and 0.65 (0.34-0.83) respectively. After restricting to 23 non-Hispanic Caucasian subjects, the ICC was 0.75 (0.64-0.90) and slightly stronger pairwise correlations were observed: the correlation coefficients were 0.72 (0.42-0.87) for baseline vs. +1 year, 0.69 (0.37-0.87) for +1 year vs. +5 years, 0.58 (0.18-0.81) for baseline vs. +5 years, and 0.70 (0.37-0.87) for the average of baseline and +1 year vs. +5 years. These findings suggest that serum 25(OH)D concentration at a single time point may be a useful biomarker of long-term vitamin D status in population-based studies of various diseases. When possible, investigators might also consider taking multiple measurements from each subject at different times to reduce misclassification of vitamin D status, thereby improving the validity of risk estimates. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3770.