Standardizing 25-hydroxyvitamin D data from the HunMen cohort.

Standardization of 25-hydroxyvitamin D (25OHD) values is still a challenge. We propose standardization by correction of the measured 25OHD values using the linear regression bias from the National Institute of Standards and Technology (NIST) 'total' target values reported by Vitamin D External Quality Assessment Scheme (DEQAS). Our approach could perhaps be a practical solution to the anomaly surrounding non-standardized 25OHD values. INTRODUCTION: Standardization of 25OHD values is still a challenge. We propose standardization by correction of the measured 25OHD values using the linear regression equation derived from the analysis of relationship between total 25OHD values measured by the methodology used by the laboratory and the NIST total target values (TV) reported by the DEQAS for all 5 of the DEQAS samples in a given survey. METHODS: We applied our approach to standardize total 25OHD values of the HunMen cohort. RESULTS: All 206 samples for the HunMen cohort were evaluated using the automated Liaison DiaSorin total 25OHD chemiluminescence immunoassay (CLIA). The timing of these measurements coincided with that of the October 2015 DEQAS survey using samples 481 to 485. Following standardization, the mean total 25OHD changed from 53 to 62 nmol/L and the prevalence of hypovitaminosis D (<75 nmol/L) decreased significantly from 84 to 72%. CONCLUSION: A simple approach readily applicable at the routine diagnostic laboratory could perhaps be a practical solution to the anomaly surrounding non-standardized 25OHD values.

Ultraviolet radiation and effects on humans: the paradigm of maternal vitamin D production during pregnancy.

Current evidence indicates that neonates born of mothers with vitamin D deficiency during pregnancy have greater risk for developing hypocalcemia, rickets and extra-skeletal disorders. Despite the classic knowledge that ultraviolet-B (UVB) exposure is the most efficient way for a future mother to obtain optimal vitamin D concentrations, no current consensus or clinical recommendations exist regarding the duration and timing of UVB exposure for pregnant women. This article offers a narrative review of available data regarding how UVB exposure affects maternal vitamin D production during pregnancy, along with a discourse on clinical implications of this public health issue. Future studies would benefit from adopting UVB exposure estimates to recommend appropriate UVB exposure to pregnant women. Doing so could provide a more holistic and practical approach in managing maternal hypovitaminosis D during pregnancy.

Hypovitaminosis D in pregnancy in the Mediterranean region: a systematic review.

Despite high levels of sunshine, maternal hypovitaminosis D during pregnancy is prevalent in the Mediterranean region. The aim of this study is to systematically review trials that investigated vitamin D concentrations during pregnancy in this region, in order to determine predictors of hypovitaminosis D and explain this phenomenon. After applying inclusion/exclusion criteria, 15 studies were entered into the systematic review involving 2649 pregnant women and 820 neonates. The main outcome was maternal vitamin D status, assessed by serum 25-hydroxy-vitamin D (25(OH)D) concentrations. Possible predictors of the outcome included maternal age, body mass index (BMI), race, socioeconomic status, skin type, gestational age, sun exposure, calcium and vitamin D intake and supplementation, smoking status, parity and season of delivery. Studies differed widely in vitamin D deficiency criteria, method of measurement and outcomes. The prevalence of vitamin D insufficiency ranges from 9.3 to 41.4%, whereas that of vitamin D deficiency from 22.7 to 90.3%. A positive association with 25(OH)D concentrations exists for light skin color, white race, uncovered dressing pattern, maternal vitamin D supplementation and season of gestation (spring/summer). An inverse association exists for BMI and gestational age, whereas data for smoking and socioeconomic status are controversial. We concluded that vitamin D deficiency in pregnancy seems to be quite common, even in the Mediterranean region. Racial, social and cultural habits, as well as the absence of preventive supplementation/dietary strategies, seem to negate the benefits of sun exposure.

Vitamin D and cutaneous lupus erythematosus: effect of vitamin D replacement on disease severity.

BACKGROUND: The main vitamin D source is exposure to ultraviolet radiation, which aggravates cutaneous lupus erythematosus (CLE). OBJECTIVES: The aims of this study were to identify variables associated with lower serum 25-hydroxyvitamin D [25(OH)D] levels in CLE patients and assess the effect of vitamin D restoration on disease severity. METHODS: Vitamin D status in 60 CLE patients and 117 apparently healthy subjects was compared. We recommended oral vitamin D3 to 27 CLE patients. After one year of treatment, changes in disease severity were assessed and compared to 25 untreated CLE patients. Disease severity was measured by the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI), number of exacerbations, duration of active lesions and patient assessment. RESULTS: Presence of CLE raised the odds of having vitamin D deficiency (OR 3.47, 95% CI 1.79-6.69). Increasing age and disease duration were associated with higher odds of having vitamin D deficiency. After a one-year follow-up, disease activity improved in the treatment group (CLASI A 2.7 ± 2.9 vs. 0.9 ± 1.4) (p = 0.003), as confirmed by the patient assessment (p = 0.01). CONCLUSIONS: Vitamin D inadequacy is more prevalent in CLE participants than in healthy controls. Treating vitamin D insufficiency is associated with improved disease severity according to physician and patient assessments.

An estimate of the global reduction in mortality rates through doubling vitamin D levels.

BACKGROUND/OBJECTIVES: The goal of this work is to estimate the reduction in mortality rates for six geopolitical regions of the world under the assumption that serum 25-hydroxyvitamin D (25(OH)D) levels increase from 54 to 110 nmol/l. SUBJECTS/METHODS: This study is based on interpretation of the journal literature relating to the effects of solar ultraviolet-B (UVB) and vitamin D in reducing the risk of disease and estimates of the serum 25(OH)D level-disease risk relations for cancer, cardiovascular disease (CVD) and respiratory infections. The vitamin D-sensitive diseases that account for more than half of global mortality rates are CVD, cancer, respiratory infections, respiratory diseases, tuberculosis and diabetes mellitus. Additional vitamin D-sensitive diseases and conditions that account for 2 to 3% of global mortality rates are Alzheimer's disease, falls, meningitis, Parkinson's disease, maternal sepsis, maternal hypertension (pre-eclampsia) and multiple sclerosis. Increasing serum 25(OH)D levels from 54 to 110 nmol/l would reduce the vitamin D-sensitive disease mortality rate by an estimated 20%. RESULTS: The reduction in all-cause mortality rates range from 7.6% for African females to 17.3% for European females. Reductions for males average 0.6% lower than for females. The estimated increase in life expectancy is 2 years for all six regions. CONCLUSIONS: Increasing serum 25(OH)D levels is the most cost-effective way to reduce global mortality rates, as the cost of vitamin D is very low and there are few adverse effects from oral intake and/or frequent moderate UVB irradiance with sufficient body surface area exposed.