Sufficient 25OHD Levels Research Articles

Vitamin D status and its determinants in pregnant women form the Faroe Islands

Abstract Background In regions like the Faroe Islands, where sunlight may be insufficient for vitamin D synthesis, alternative sources such as diet and supplements become crucial. This study focuses on assessing the vitamin D status of pregnant women in the Faroe Islands during the early second trimester, considering the potential implications for maternal and fetal health. Methods A nationwide cross-sectional study (June 2020-April 2022) with 652 women providing blood samples and a questionnaire on demographics, vitamin D intake, and diet. Binary logistic regression assessed predictors of low 25-hydroxyvitamin D (25OHD) levels (<50nmol/L). Plasma 25OHD concentrations were analysed at the local National Hospital using the Alinity i 25-OH Vitamin D assay, employing chemiluminescence microparticle immunoassay (CMIA) for quantitative determination. Results The mean age was 30.7 (SD, 4.9) years; 86% were locally born; 45% resided in the capital area; 49% were overweight (BMI ≥25.0), with a mean pre-pregnancy BMI of 26.0. Most participants (95%) reported vitamin D intake (median of 10µg/day) and consumed vitamin D-rich foods 5.3 times per week. Low 25OHD concentrations were observed in 26% of participants, associated with residency, vitamin D intake, dietary habits, overweight, and sampling time. Maternal age, education, BMI, smoking, and traditional food showed no significant associations. During winter, vitamin D intake correlated more strongly with plasma 25OHD levels (Spearman’s rho, winter: 0.4, p < 0.001; summer: 0.2, p = 0.002). Conclusions Our study’s findings are essential for the health of Faroese pregnant women. 74% of them had sufficient 25OHD levels, which is encouraging. However, low levels were associated with residence, diet, overweight, and winter. This underscores the need for public health efforts to focus on monitoring vitamin D status, promoting vitamin D-rich foods, especially in winter, and monitoring dietary intake to protect maternal and fetal health. Key messages • No previous data on vitamin D status in Faroese pregnant women. • Seasonal variation is observed.

The Effect of Vitamin D Supplementation in Pregnant Women with Overweight and Obesity: A Randomised Controlled Trial.

The impact of vitamin D supplementation on 25-hydroxyvitamin D (25OHD) levels, metabolic status, and pregnancy outcomes in pregnant women with overweight and obesity (OW/OB) is uncertain. This study aimed to examine whether administrating 800 IU of vitamin D3 orally would improve maternal serum 25OHD levels, lipid profile, and pregnancy outcomes compared to 400 IU. This was a two-arm, parallel, non-blinded randomised controlled trial involving 274 pregnant women recruited from KK Women's and Children's Hospital, with a body mass index of ≥25 kg/m2 within 16 weeks gestation. The participants were randomly assigned to receive 800 IU/day (intervention group) or 400 IU/day (control group) of oral vitamin D3 supplements. The primary outcomes were maternal serum 25OHD and lipid levels at 24-28 weeks gestation. The secondary outcomes included maternal and birth outcomes. Compared with controls (n = 119), the intervention group (n = 112) exhibited higher 25OHD levels at 24-28 weeks gestation (adjusted mean difference 6.52 nmol/L; 95% confidence interval 2.74, 10.31). More women in the intervention group achieved sufficient 25OHD levels (77.7% vs. 55.5%; p < 0.001). No differences were observed in lipid profiles or maternal or birth outcomes between the groups. An additional 400 IU of oral vitamin D3 supplementation increased serum 25OHD levels but did not impact lipid profiles or pregnancy outcomes.

25-hydroxyvitamin D level is associated with greater grip strength across adult life span: a population-based cohort study.

Maintaining muscle function throughout life is critical for healthy ageing. Although in vitro studies consistently indicate beneficial effects of 25-hydroxyvitamin D (25-OHD) on muscle function, findings from population-based studies remain inconclusive. We therefore aimed to examine the association between 25-OHD concentration and handgrip strength across a wide age range and assess potential modifying effects of age, sex and season. We analysed cross-sectional baseline data of 2576 eligible participants out of the first 3000 participants (recruited from March 2016 to March 2019) of the Rhineland Study, a community-based cohort study in Bonn, Germany. Multivariate linear regression models were used to assess the relation between 25-OHD levels and grip strength while adjusting for age, sex, education, smoking, season, body mass index, physical activity levels, osteoporosis and vitamin D supplementation. Compared to participants with deficient 25-OHD levels (<30 nmol/L), grip strength was higher in those with inadequate (30 to <50 nmol/L) and adequate (≥50 to ≤125 nmol/L) levels (ßinadequate = 1.222, 95% CI: 0.377; 2.067, P = 0.005; ßadequate = 1.228, 95% CI: 0.437; 2.019, P = 0.002). Modelling on a continuous scale revealed grip strength to increase with higher 25-OHD levels up to ~100 nmol/L, after which the direction reversed (ßlinear = 0.505, 95% CI: 0.179; 0.830, P = 0.002; ßquadratic = -0.153, 95% CI: -0.269; -0.038, P = 0.009). Older adults showed weaker effects of 25-OHD levels on grip strength than younger adults (ß25OHDxAge = -0.309, 95% CI: -0.594; -0.024, P = 0.033). Our findings highlight the importance of sufficient 25-OHD levels for optimal muscle function across the adult life span. However, vitamin D supplementation should be closely monitored to avoid detrimental effects.

Associations between Serum 25-Hydroxyvitamin D Levels and Health-Related Quality-of-Life Measures in Patients with Breast Cancer: A Longitudinal Study.

Recent evidence suggests that vitamin D might lower breast cancer mortality. There is also growing interest in vitamin D's potential association with health-related quality-of-life (HRQoL). Associations between circulating 25-hydroxyvitamin D (25OHD) concentrations and HRQoL were examined prospectively among breast cancer survivors at the time of diagnosis and 1 year later. 504 women with incident early-stage breast cancer at Roswell Park Comprehensive Cancer Center were included, and 372 patients provided assessments 1 year later. At each timepoint, participants provided blood samples and completed the SF-36 Health Survey, and surveys on perceived stress, depression, and fatigue. Season-adjusted serum 25OHD concentrations were analyzed in relation to HRQoL measures using multivariable logistic regression models. Approximately 32% of participants had deficient vitamin D levels at diagnosis, which decreased to 25% at 1 year. Concurrently, although SF-36 physical health summary scores were lower at 1 year, mental health summary scores improved, and levels of depression and perceived stress were lower. In comparison with women with sufficient 25OHD levels (>30 ng/mL) at diagnosis, those who were deficient (<20 ng/mL) had significantly worse HRQoL at diagnosis and 1 year later. Vitamin D deficiency 1 year post-diagnosis was also associated with worse HRQoL, particularly among breast cancer survivors who took vitamin D supplements. Breast cancer survivors with vitamin D deficiency were more likely to report lower HRQoL than those with sufficient levels at the time of diagnosis and 1 year post-diagnosis. Our results indicate a potential benefit of vitamin D supplementation for improving breast cancer survivorship.

Body composition in nonobese individuals according to vitamin D level.

Obesity is associated with lower 25-hydroxyvitamin D (25OHD) levels, but the association between 25OHD deficiency and specific body composition (BC) patterns remains unclear. The aim of this study was to analyze the correlation between 25OHD levels and BC in a population of healthy, nonobese individuals. Cross-sectional, observational study including a convenience sample of community-dwelling healthy individuals aged ≥18 years who responded to a study advertisement and were randomly selected. The participants filled out a questionnaire and had fasting blood drawn and anthropometric indices taken. Dual-energy x-ray absorptiometry was performed for BC analysis (fat and lean body mass). The subjects were divided according to 25OHD levels into three groups: I (≤20 ng/mL, vitamin D deficient), II (>20 and <30 ng/mL, vitamin D insufficient), and III (≥30 ng/mL, vitamin D sufficient). Of 299 individuals selected, 51 were excluded, yielding a final sample of 248 (128 women) who had serum 25OHD levels measured. Women presented higher 25OHD levels than men (27.8±12.0 ng/mL and 24.8±11.3 ng/mL, respectively; p = 0.03). Including both sexes, Group I had greater body mass index (BMI; 26.6±2.5 kg/m2) and waist circumference (WC; 91.8.8±9.1 cm) compared with the other groups. Group I also had 75.7% and 65.3% of abnormal BMI and WC values, respectively, (p<0.05 for both) and a higher percentage of trunk and android fat confirmed by multivariate analysis. No differences in BC were observed in individuals with insufficient versus sufficient 25OHD levels. Individuals with lower 25OHD levels had increased fat in the android region and trunk. This study confirms the association of lower 25OHD levels with greater BMI and WC and increased deposition of fat in body compartments, which, even in nonobese individuals, are commonly associated with increased metabolic risk.

Influence of the Mediterranean Diet on 25-Hydroxyvitamin D Levels in Adults

The Mediterranean diet (MD) is a dietary pattern effective in terms of prevention of obesity-related diseases, and represents the gold standard in preventive medicine, due to the synergistic action of many nutrients with antioxidant and anti-inflammatory properties. In addition, excess body weight significantly increases the risk of hypovitaminosis D, a well-recognized common feature of individuals with obesity. It is well-known that there is a clear gender difference in the adherence to the MD. The aim of this study was to investigate the association between adherence to the MD and 25-hydroxyvitamin D (25OHD) levels in adults, according to gender. Study population consisted of 617 participants; 296 were males and 321 were females, matched by age and body mass index (BMI). A validated 14-item questionnaire PREDIMED (Prevención con dieta Mediterránea) was used for the assessment of adherence to the MD. The 25OHD levels were determined by a direct competitive chemiluminescence immunoassay. Females have a higher PREDIMED score than males (7.4 ± 2.8 vs. 6.7 ± 3.1 score, p = 0.001), and according to PREDIMED categories, a greater percentage of males had low adherence to the MD compared to their female counterparts (40.2% vs. 37.1%; χ2 = 8.94, p = 0.003). The 25OHD levels were higher in males than in females (18.3 ± 7.3 vs. 16.8 ± 7.8 ng/mL, p = 0.01), and a higher percentage of males had sufficient 25OHD levels (>30 ng/mL) than their female counterparts (10.5% vs. 3.4%, χ2 = 10.96, p < 0.001). Stratifying the sample population according to 25OHD categories, BMI decreased and PREDIMED score increased significantly along with the increased 25OHD levels, in both males and females, respectively (p < 0.001). Looking at the bivariate correlations, PREDIMED score was positively correlated with 25OHD levels after adjusting for age and BMI, in both males (r = 0.21, p < 0.001) and females (r = 0.30, p < 0.001). At the bivariate proportional odds ratio (OR) model, 25OHD levels presented the highest OR values in the category low adherence vs. high adherence to the MD, in both genders (OR 1.21 and OR 1.31, in males and females, respectively). Receiver operator characteristic (ROC) analysis was performed to determine the cut-off values of PREDIMED scores predictive of 25OHD levels: PREDIMED score >5 in males (p < 0.001) and >7 in females (p < 0.001) could serve as thresholds for 25OHD levels above the median. The results of our study highlighted a novel positive association between adherence to the MD and 25OHD levels in both genders. Although 25OHD levels were higher in males than females, 69.7% were deficient. To the best of our knowledge, this is the first study to show that high adherence to the MD is associated with low BMI and high 25OHD levels in both genders, probably through the anti-inflammatory and anti-oxidant effects that are synergistically exerted by either MD or vitamin D on body weight.

Association Between Vitamin D, Frailty, and Progression of Frailty in Community-Dwelling Older Women.

Vitamin D (25OHD) is involved in many physiological functions that decline with age, contributing to frailty and increased risk for negative health outcomes. Whether 25OHD is a long-term risk marker for frailty over a longer time and whether it is consistent with advancing age is unclear. To investigate the association between 25OHD and frailty in older women followed for 10 years. Prospective, population-based, cohort study in Malmö, Sweden. Community-dwelling women, age 75 years (N = 1044) with reassessments at ages 80 (n = 715) and 85 (n = 382) years. Frailty was quantified using a 10-variable frailty index. Women were categorized as 25OHD insufficient (<50 nmol/L) or sufficient (≥50 nmol/L). At ages 75 and 80 years, women with insufficient 25OHD were frailer than women with sufficient 25OHD (0.23 vs 0.18, P < 0.001; and 0.32 vs 0.25, P = 0.001, respectively). At age 80 years, 25OHD insufficiency was associated with subsequent frailty 5 years later (0.41 vs 0.32; P = 0.011). Accelerated progression of frailty was not associated with lower 25OHD levels, and 25OHD level >75 nmol/L was not additionally beneficial with regard to frailty. No association between 25OHD and frailty was observed at age 85 years. Within the frailty index, variables associated with 25OHD were related to muscle strength and function. In this study, 25OHD insufficiency was associated with increased frailty in all but the oldest old. This study supports the value of maintaining sufficient 25OHD levels for healthy aging.

Ionized Calcium Cannot Predict Vitamin D Deficiency

To the Editor, Vitamin D deficiency (VDD) results from inadequate intake, lack of sun exposure, malabsorption, or genetic abnormalities in vitamin D metabolism. Vitamin D deficiency/insufficiency remains undiagnosed, unless 25-hydroxy vitamin D (25OHD) concentrations are measured. Previously VDD was considered to be prevalent in regions where there was not ample sunlight [1]. However, recent literature suggests extensive VDD in many of the sun drenched countries [2, 3]. Arya et al. [4] reported 78.3% of the healthy hospital staff had 25OHD levels <50 mmol/l in Lucknow India despite abundance of sunshine. Reports from Pakistan have similarly shown high prevalence of 25OHD deficiency [5, 6]. In VDD, plasma calcium is maintained at the expense of bone calcium but persistence of deficiency leads to fall in calcium level and secondary hyperparathyroidism. We reported 30% of asymptomatic adults with 25OHD deficiency and secondary hyperparathyroidism but normal calcium levels [6]. In another report on medical clinic patients, calcium was low in patients with severe VDD only and remained normal in patients with mild and moderate deficiency [5]. However, these studies measured total calcium while the true calcaemic status of individuals is best assessed by ionized calcium. We determined whether measurement of iCa could detect VDD in blood samples from 40 apparently healthy laboratory staff aged 27 ± 5 years and with no known comorbid. None of the individuals were on any medications including calcium and vitamin D supplements. Blood samples were collected according to recommendations by Clinical and Laboratory Standards Institute (CLSI), iCa and pH were simultaneously along with estimation of 25OHD levels by chemiluminescence methodology. Ninety percent of the group was 25OHD deficient (25OHD < 50 nmol/l). Subjects with insufficient and sufficient 25OHD levels were 5% each. The difference between mean iCa results in 25OHD deficient, insufficient and sufficient groups were non-significant. Negative poor correlation was observed between iCa and 25OHD levels. VDD has been widely reported in immigrant Pakistanis to Europe and America. It was suggested that Pakistanis living within homeland are not suffering from VDD as Pakistan is situated between 24° and 37° north latitude and has adequate sunshine. Findings of this study has demonstrated that majority of the healthy population is vitamin D deficient and despite VDD has normal iCa levels, which could be at the expense of mobilization of bone calcium by secondary hyperparathyroidism. These results support the findings of Singh et al. [7] who reported poor correlation between 25OHD insufficiency and other analytes including plasma calcium, alkaline phosphatase or phosphorus levels. Ionized calcium estimation though technically demanding cannot detect VDD/insufficiency. To assess calcium status, total calcium provides enough information. Focus should be on optimization of vitamin D and calcium intake, either by diet or supplementation in our population.

High prevalence of vitamin D deficiency despite supplementation in premenopausal women with breast cancer undergoing adjuvant chemotherapy.

Vitamin D deficiency is associated with increased breast cancer risk and decreased breast cancer survival. The purpose of this study was to determine the prevalence of vitamin D deficiency, as measured by serum 25-hydroxyvitamin D (25-OHD), in premenopausal women at initiation of adjuvant chemotherapy for breast cancer and after 1 year of vitamin D supplementation. The study included 103 premenopausal women from the northeastern United States with stages I to III breast cancer who received adjuvant chemotherapy and participated in a 1-year zoledronate intervention trial. All patients were prescribed vitamin D(3) (cholecalciferol) 400 IU and calcium carbonate 1,000 mg daily. At baseline and at 6 and 12 months, bone mineral density (BMD) measurements were obtained and blood was collected and analyzed in batches for serum 25-OHD. Vitamin D deficiency was defined as serum 25-OHD less than 20 ng/mL, insufficiency as 20 to 29 ng/mL, and sufficiency as 30 ng/mL or greater. At baseline, 74% of women were vitamin D deficient (median, 17 ng/mL). Vitamin D deficiency was slightly less common in white women (66%) compared with black (80%) and Hispanic (84%) women. After vitamin D supplementation for 1 year, less than 15% of white and Hispanic women, and no black women, achieved sufficient 25-OHD levels. Vitamin D levels did not correlate with baseline BMD and were not altered by chemotherapy or bisphosphonate use. Vitamin D deficiency is highly prevalent in women with breast cancer. The current recommended dietary allowance of vitamin D is too low to increase serum 25-OHD greater than 30 ng/mL. Optimal dosing for bone health and, possibly, improved survival has yet to be determined.