METHODS: Predialysis CKD patients were included in this cross-sectional study. Patient demographics, medical/medication histories, and laboratory parameters (serum 25-hydroxyvitamin D (25(OH)D), creatinine, phosphate (P), calcium, albumin, and intact-PTH (i-PTH)) were collected and compared among patients with various CKD stages. The association between 25(OH)D and these parameters was determined by multiple linear regression.
RESULTS: A total of 196 patients with mean ± SD eGFR of 26.4 ± 11.2 mL/min/1.73 m2 was included. Vitamin D deficiency (25(OH)D concentration < 15 ng/mL) and insufficiency (25(OH)D concentration 16 - 30 ng/mL) was found in 29.1% and 57.7% of the patients, respectively. Mean ± SD serum 25(OH)D was 20.8 ± 9.3 ng/mL. Female patients had lower vitamin D concentrations than males (16.9 ng/mL vs. 23.9 ng/mL; p < 0.001). Vitamin D levels were also higher in Chinese (22.3 ng/mL) than Malay (17.3 ng/mL) and Indian (13.1 ng/mL) patients (p < 0.05). Nonadjusted analyses showed higher i-PTH concentration in vitamin D deficient patients (p < 0.05).
CONCLUSION: Despite being a sun-rich country all year round, the majority (86.8%) of predialysis CKD patients in Singapore have suboptimal vitamin D status. Lower vitamin D concentrations were found in females and in those with darker skin tone. Vitamin D deficient patients also tended to have higher i-PTH levels.
METHODS: This prospective cross-sectional study involved 70 patients with diabetic nephropathy; 40 were categorized into the group with nondeficient serum 25-hydroxyvitamin D levels [25(OH)D >50 nmol/l], whereas 30 patients were categorized to the group with deficient serum 25(OH)D (<50 nmol/l). Microvascular endothelial function was determined using laser Doppler fluximetry and the process of iontophoresis. Acetylcholine and sodium nitroprusside were used to determine endothelium-dependent and independent vasodilatation.
RESULTS: Mean age of patients was 56.7 ± 3.8 years; 50 were men, whereas 20 were women. Mean serum 25(OH)D in the vitamin D-nondeficient group was 69.4 ± 2.9 nmol/l; the level in the vitamin D-deficient group was 42.1 ± 1.3 nmol/l, P < 0.001. Endothelium-dependent vasodilatation was lower in the vitamin D-deficient group compared with the vitamin D-nondeficient group (23.6 ± 2.7 versus 37.3 ± 3.8 arbitrary units, P = 0.004). No significant differences were observed between the two groups in their hsCRP levels, mean age, estimated glomerular filtration rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP) and glycosylated haemoglobin.
CONCLUSION: Microvascular endothelial function was significantly reduced in diabetic nephropathy patients with deficient vitamin D levels compared with those with nondeficient levels.
METHODS: A cross sectional study was carried out among first trimester pregnant women during their first antenatal visit. Samples were taken from different ethnicities in an urban district in Malaysia. A total of 396 respondents (99 % response rate) aged 18-40 years completed self-administered and guided questionnaire (characteristics and risk factors), validated semi-quantitative food frequency questionnaire for vitamin D in Malaysia (FFQ vitamin D/My), anthropometric measures (weight and height), blood test for serum 25(OH)D, skin measurement using Mexameter (MX 18) and Fitzpatrick Skin Type Chart Measurement (FSTCM). Data were analyzed to determine the association between risk factors and hypovitaminosis D.
RESULTS: The prevalence of hypovitaminosis D (serum 25(OH)D D were Malay ethnicity (OR 33.68; 95 % CI: 12.81, 88.56), Indian ethnicity (OR 16.86; 95 % CI: 3.78,75.20), secondary education (OR 12.12; 95 % CI: 2.71, 54.16) and tertiary education (OR 14.38; 95 % Cl: 3.31, 62.45).
CONCLUSION: Awareness should be raised among Malay and Indian pregnant women with secondary and tertiary education who consumed vitamin D (especially milk) poorly in order to prevent adverse health outcomes. Further studies need to be conducted among health care workers to determine their level of knowledge related to vitamin D, as they are front liner in detecting the hypovitaminosis D.
METHODS: A case-control study to examine serum 25- hydroxyvitamin D [25(OH)D] levels in children with and without AD was done. Serum 25-hydroxyvitamin D [25(OH)D] level was measured by immunoassay. AD severity was evaluated using the SCORing Atopic Dermatitis (SCORAD) index.
RESULTS: The serum levels of 25(OH)D, measured in 135 children with AD was not statistically different from 65 children without AD [median (IQR): 25.2ng/mL (15.45) vs 25.9ng/mL (15.87), p=0.616]. However, serum vitamin D levels were significantly lower in children with severe AD compared to those with mild-to-moderate AD [median (IQR): 16.0ng/mL (19.32) vs 26.3ng/mL (15.56), p=0.021]. The odds of having vitamin D deficiency in children with severe AD was 3.82 times that of children with non-severe AD (95% confidence level: 1.13, 12.87).
CONCLUSION: This study suggests that there is an inverse association between vitamin D level and the severity of AD in Malaysian children.
METHODS: Cross-sectional study of Malaysian ambulant CWE on antiseizure medication for >1 year. Sixteen SNPs in 8 genes (GC, VDR, CYP2R1, CYP24A1, CYP27B1, CYP27A1, CYP3A4, NADSYN1/DHCR7) were genotyped. Linear and logistic regression models and co-variates adjusted analyses were used. SNPs with significant associations were further analysed in a group of ethnically-matched healthy Malaysian children.
RESULTS: 239 CWE were recruited (52.7% Malay, 24.3% Chinese and 23.0% Indian) with mean serum 25(OH)D of 58.8 nmol/L (SD 25.7). Prevalence of vitamin D deficiency (≤37.5 nmol/L) was 23.0%. Minor allele of GC-rs4588-A was associated with lower serum 25(OH)D in the meta-analysis of both CWE (β -8.11, P = 0.002) and Malaysian healthy children (β -5.08, P < 0.001), while VDR-rs7975232-A was significantly associated with reduced odds of vitamin D deficiency in Malay subgroup of CWE (OR: 0.16; 95% CI: 0.06-0.49; P = 0.001) and this association was not found in the healthy children group.
CONCLUSIONS: Our results suggest that GC-rs4588 is associated with lower serum 25(OH)D concentration in both Malaysian CWE and healthy children, while VDR-rs7975232A is associated with lower risk of vitamin D deficiency in Malaysian CWE of Malay ethnicity. Our findings may assist in the genetic risk stratification of low vitamin D status among CWE.
OBJECTIVES: To investigate the effects of vitamin D supplementation in children and adults with SCD and to compare different dose regimens. To determine the effects of vitamin D supplementation on general health (e.g. growth status and health-related quality of life), on musculoskeletal health (including bone mineral density, pain crises, bone fracture and muscle health), on respiratory health (including lung function, acute chest syndrome, acute exacerbation of asthma and respiratory infections) and the safety of vitamin D supplementation.
SEARCH METHODS: We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 19 March 2020. We also searched database such as PubMed, clinical trial registries and the reference lists of relevant articles and reviews. Date of last search: 14 January 2020.
SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs comparing oral administration of any form of vitamin D supplementation at any dose and for any duration to another type or dose of vitamin D or placebo or no supplementation in people with SCD, of all ages, gender, and phenotypes.
DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data and assessed the risk of bias of the included studies. They used the GRADE guidelines to assess the quality of the evidence.
MAIN RESULTS: Vitamin D versus placebo One double-blind RCT (n = 39) compared oral vitamin D3 (cholecalciferol) supplementation (20 participants) to placebo (19 participants) for six weeks. Only 25 participants completed the full six months of follow-up. The study had a high risk of bias due to incomplete outcome data, but a low risk of bias for randomisation, allocation concealment, blinding (of participants, personnel and outcome assessors) and selective outcome reporting; and an unclear risk of other biases. Vitamin D supplementation probably led to higher serum 25(OH)D levels at eight weeks, mean difference (MD) 29.79 (95% confidence interval (CI) 26.63 to 32.95); at 16 weeks, MD 12.67 (95% CI 10.43 to 14.90); and at 24 weeks, MD 15.52 (95% CI 13.50 to 17.54) (moderate-quality evidence). There was little or no difference in adverse events (tingling of lips or hands) between the vitamin D and placebo groups, risk ratio 3.16 (95% CI 0.14 to 72.84) (low-quality evidence). Vitamin D supplementation probably caused fewer pain days compared to the placebo group at eight weeks, MD -10.00 (95% CI -16.47 to -3.53) (low-quality evidence), but probably led to a lower (worse) health-related quality of life score (change from baseline in physical functioning PedsQL scores); at both 16 weeks, MD -12.56 (95% CI -16.44 to -8.69) and 24 weeks, MD -12.59 (95% CI -17.43 to -7.76), although this may not be the case at eight weeks (low-quality evidence). Vitamin D supplementation regimens compared Two double-blind RCTs (83 participants) compared different regimens of vitamin D. One RCT (n = 62) compared oral vitamin D3 7000 IU/day to 4000 IU/day for 12 weeks, while the second RCT (n = 21) compared oral vitamin D3 100,000 IU/month to 12,000 IU/month for 24 months. Both RCTs had low risk of bias for blinding (of participants, personnel and outcome assessors) and incomplete outcome data, but the risk of selective outcome reporting bias was high. The bias from randomisation and allocation concealment was low in one study but not in the second. There was an unclear risk of other biases. When comparing oral vitamin D 100,000 IU/month to 12,000 IU/month, the higher dose may have resulted in higher serum 25(OH)D levels at one year, MD 16.40 (95% CI 12.59 to 20.21) and at two years, MD 18.96 (95% CI 15.20 to 22.72) (low-quality evidence). There was little or no difference in adverse events between doses (low-quality evidence). There were more episodes of acute chest syndrome in the high-dose group, at one year, MD 0.27 (95% CI 0.02 to 0.52) but there was little or no difference at two years, MD 0.09 (95% CI -0.04 to 0.22) (moderate-quality evidence). At one year and two years there was also little or no difference between the doses in the presence of pain (moderate-quality evidence) or forced expiratory volume in one second % predicted. However, the high-dose group had lower values for % predicted forced vital capacity at both one and two years, MD -7.20% predicted (95% CI -14.15 to -0.25) and MD -7.10% predicted (95% CI -14.03 to -0.17), respectively. There were little or no differences between dose regimens in the muscle health of either hand or the dominant hand. The study comparing oral vitamin D3 7000 IU/day to 4000 IU/day (21 participants) did not provide data for analysis, but median serum 25(OH)D levels were reported to be lower in the low-dose group at both six and 12 weeks. At 12 weeks the median serum parathyroid hormone level was lower in the high-dose group.
AUTHORS' CONCLUSIONS: We included three RCTs of varying quality. We consider that the current evidence presented in this review is not of sufficient quality to guide clinical practice. Until further evidence becomes available, clinicians should consider the relevant existing guidelines for vitamin D supplementation and dietary reference intakes for calcium and vitamin D. Well-designed RCTs of parallel design, are required to determine the effects and the safety of vitamin D supplementation as well as to assess the relative benefits of different doses in children and adults with SCD.
METHODS: Cross-sectional study of ambulant children with epilepsy on long-term AEDs for >1 year seen in three tertiary hospitals in Malaysia from April 2014 to April 2015. Detailed assessment of pubertal status, skin pigmentation, sunshine exposure behavior, physical activity, dietary vitamin D and calcium intake, anthropometric measurements and bone health blood tests (vitamin D, alkaline phosphatase, calcium, phosphate, and parathyroid hormone levels) were obtained on all patients. Vitamin D deficiency was defined as 25-hydroxy vitamin D [25(OH)D] levels ≤35 nmol/L and insufficiency as 25(OH)D levels of 36-50 nmol/L.
RESULTS: A total of 244 children (146 male) participated in the study. Ages ranged between 3.7 and 18.8 years (mean 12.3 years). 25(OH)D levels ranged between 7.5 and 140.9 nmol/L (mean 53.9 nmol/L). Vitamin D deficiency was identified in 55 patients (22.5%), and a further 48 (19.7%) had vitamin D insufficiency. Multivariate logistic regression analysis identified polytherapy >1 AED (odds ratio [OR] 2.16, 95% confidence interval [CI] 1.07-4.36), age >12 years (OR 4.16, 95% CI 1.13-15.30), Indian ethnicity (OR 6.97, 95% CI 2.48-19.55), sun exposure time 30-60 min/day (OR 2.44, 95% CI 1.05-5.67), sun exposure time <30 min/day (OR 3.83, 95% CI 1.61-9.09), and female (OR 2.61, 95% CI 1.31-5.20) as statistically significant (p < 0.05) risk factors for vitamin D deficiency.
SIGNIFICANCE: Despite living in the tropics, a high proportion of Malaysian children with epilepsy are at risk of vitamin D deficiency. Targeted strategies including vitamin D supplementation and lifestyle advice of healthy sunlight exposure behavior should be implemented among children with epilepsy, particularly for those at high risk of having vitamin D deficiency.
OBJECTIVES: To describe the status and predictors of vitamin D status in healthy Nepalese mothers and infants.
METHODS: 500 randomly selected Nepalese mother and infant pairs were included in a cross-sectional study. Plasma 25(OH)D concentrations were measured by LC-MS/MS and multiple linear regression analyses were used to identify predictors of vitamin D status.
RESULTS: Among the infants, the prevalence of vitamin D insufficiency (25(OH)D <50 nmol/L) and deficiency (<30 nmol/L) were 3.6% and 0.6%, respectively, in contrast to 59.8% and 14.0% among their mothers. Infant 25(OH)D concentrations were negatively associated with infant age and positively associated with maternal vitamin D status and body mass index (BMI), explaining 22% of the variability in 25(OH)D concentration. Global solar radiation, maternal age and BMI predicted maternal 25(OH)D concentration, explaining 9.7% of its variability.
CONCLUSION: Age and maternal vitamin D status are the main predictors of vitamin D status in infants in Bhaktapur, Nepal, who have adequate vitamin D status despite poor vitamin D status in their mothers.
METHODS: 100 CKD stage 3-4 patients were included in the study. Direct chemiluminesent immunoassay was used to determine the level of serum 25-hydroxyvitamin D. All subjects underwent a carotid ultrasound to measure common carotid artery intima-media thickness (CCA-IMT) and to assess the presence of carotid plaques or significant stenosis (≥50 %). Vitamin D deficiency was defined as serum 25-hydroxyvitamin D vitamin D deficiency and non-deficiency groups did not differ significantly in terms of abnormal CCA-IMT (P = 0.443), carotid plaque (P = 0.349), and carotid stenosis (P = 0.554). No significant correlation between serum 25-hydroxyvitamin D levels and CCA-IMT (P = 0.693) was found. On a backward multiple linear regression model, serum 25-hydroxyvitamin D levels was not associated with CCA-IMT, abnormal CCA-IMT, or plaque presence.
CONCLUSIONS: No important association between serum 25-hydroxyvitamin levels and carotid atherosclerosis was found in CKD patients.
EVIDENCE ACQUISITION: We conducted a meta-analysis to evaluate the relationship between primary aldosteronism (PA) with bone biochemical markers and to assess bone mineral density in patients with primary aldosteronism.
EVIDENCE SYNTHESIS: A total of 939 subjects were examined (37.5% with PA). Patients with PA had significantly higher serum parathyroid hormone, lower serum calcium, higher urine calcium excretion and higher serum alkaline phosphatase compared to patients without PA, with no significant difference in serum vitamin D between both groups. Bone mineral density of lumbar spine, femoral neck and total neck of femur were similar between two groups. With PA treatment, there was a significant increment in serum calcium and reduction in serum parathyroid hormone.
CONCLUSIONS: PA is associated with hypercalciuria with subsequent secondary hyperparathyroidism. This potentially affects bone health. We recommend this to be part of complication screening among patients with PA.