Requirements for Vitamin D Across the Life Span

Knowledge and Practice of Pediatricians Regarding Hypovitaminosis D-A Survey across 33 European Countries

Hypovitaminosis D has been recognized as a worldwide pandemic, but there are disagreements regarding its diagnosis and treatment. This study aimed to evaluate the knowledge and practice of European pediatricians concerning vitamin D (VD) and hypovitaminosis D and their adherence to relevant guidelines. A cross-sectional study was conducted through an anonymous survey via SurveyMonkey on 304 European pediatricians. Most of the participants were general pediatricians, followed by endocrinologists and neonatologists. ESPGHAN's and the national guidelines were the most frequently used. VD testing was mostly performed in patients with skeletal, chronic kidney, and autoimmune diseases. Participants predominantly answered the questions regarding the definition of hypovitaminosis D and VD supplementation correctly, especially in children younger than 12 months. They showed the least knowledge regarding the cut off-point for the initiation of the therapy and therapeutic doses used to treat confirmed hypovitaminosis D. Participants' conflicting answers could be related to the differences between the guidelines. We consider that experts in this field should create uniform guidelines, and that those guidelines should also be promoted by national or local pediatric associations.

Vitamin D Dosing: Basic Principles and a Brief Algorithm (2021 Update)

Nowadays, in modern societies, many people can be at high risk to have low vitamin D levels. Therefore, testing of serum 25-hydroxy-vitamin D (25OH-D) levels should be performed before prescribing them vitamin D supplementation. However, in some cases the 25OH-D level assessment is not available at the right moment, e.g., due to mandatory quarantine of COVID-19 outpatients. Therefore, such patients could be advised to start taking moderate vitamin D doses (e.g., 4000 IU/day for adults), and their 25-OH-D levels could be checked later. The proposed algorithm also comprises vitamin D dosing principles when baseline 25OH-D levels are known.

Novel Phototherapy Kiosk Shows Promise as a Treatment Option for Low Vitamin D

INTRODUCTION

The purpose of this study was to demonstrate the feasibility of a phototherapy kiosk (PK) to engage community adults in health promotion and to stimulate production of circulating 25-hydroxyvitamin (OH)D as effectively as a vitamin D3 oral supplement (OS). Although optimal production of vitamin D comes from sun exposure, ultraviolet B radiation with a wavelength of 290 to 320 nm penetrates exposed skin and may produce vitamin D3 using a PK.

MATERIALS AND METHODS

A prospective study was conducted with adults randomized to either six PK treatments or D3 OS for 10 weeks. Serum 25(OH)D was drawn at baseline, 10 weeks, and 14 weeks. Primary outcome was serum 25(OH)D level. Mann-Whitney test was used to assess continuous data and Chi squared test for pairwise comparisons of categorical data. Significance was set at P < .05.

RESULTS

With 18% attrition, final sample size was 88; OS, n = 45, PK, n = 43. Sample was mostly female (60%), median age 35 years, with no differences observed between groups for age, race/ethnicity, marital status, military affiliation, or season of enrollment. Median daily intake of calcium and vitamin D was well below the recommended daily allowance for each nutrient, and group. Baseline median serum 25(OH)D levels were similar. By 10 weeks, PK median level was 30 ng/mL (interquartile range [IQR] 25.8-37.0) and OS was 26 ng/mL (IQR 21.5-30.5), P = .02. The difference in 25(OH)D levels persisted at 14 weeks; the PK group returned to baseline, 27 ng/mL (IQR 22.0-32.5), and OS group declined to 21 ng/mL (IQR 17.0-30.0), P = .02.

CONCLUSION

Programmed ultraviolet B phototherapy appears to be an efficacious alternative to oral vitamin D supplementation with consistent use.

Vitamin D and COVID-19: It is time to act

Vitamin D (VitD) deficiency is considered a global problem and might be associated with increased susceptibility to COVID-19 illness. In the light of COVID-19 pandemic, VitD might be a promising agent for fighting the SARS-CoV-2, since VitD is involved in various pathophysiological mechanisms that occur during COVID-19 infection. High-dose VitD supplementation, particularly for risk groups, could be recommended to achieve and maintain optimal (range 40-60 ng/mL) serum 25-hydroxy vitamin D levels (marker of VitD status) both for COVID-19 prevention and treatment.

Serum vitamin D and diabetic foot complications

Background: Foot complications such as ulceration and neuropathy are common complications of diabetes mellitus (DM). Previous reports have demonstrated a possible increased risk of these complications in diabetic patients with low levels of serum vitamin D.Objectctive: The purpose of this study is to compare serum vitamin D levels in diabetic patients with and without Charcot neuroarthropathy (CN), peripheral arterial disease (PAD), infection (DFI), ulceration (DFU), and peripheral neuropathy (DPN). Design: A retrospective chart review of all patients undergoing foot and ankle surgery with a history of DM over a 13 month period was performed. From this cohort, fifty subjects with CN were matched with 50 without CN and preoperative lab values were compared. A secondary evaluation was performed on the subjects' other comorbidities including PAD, DFI, DFU, and DPN. Results: Seventy-eight percent of our patients had vitamin D deficiency or insufficiency. Preoperative serum vitamin D levels were not significantly different between diabetic patients with and without CN (p = 0.55). Diabetic patients with PAD (p = 0.03), DFI (p = 0.0006), and DFU (p = 0.04) were all found to have significantly lower serum vitamin D levels than diabetic patients without these complications. Lower levels of serum albumin and higher serum creatinine were also noted with subjects with PAD, DFI, DPN, and DFU. While seasonal serum vitamin D level fluctuation was noted, this difference did not reach statistical significance with the numbers available. Conclusion: We found various lower extremity complications to be associated with low serum vitamin D including PAD, DFI, and DFU. While other studies have questioned the role of vitamin D and CN, we were unable to identify any significant difference between diabetic patients with and without Charcot neuroarthropathy. Level of evidence: Level 2.

Vitamin D3 as adjunctive therapy in the treatment of depression in tuberculosis patients: a short-term pilot randomized double-blind controlled study

OBJECTIVE

We aimed to evaluate whether high-dose cholecalciferol has beneficial effects on depression in pulmonary tuberculosis (PTB) patients.

METHODS

This pilot, randomized, and double-blind trial enrolled 123 recurrent PTB patients (aged ≥18 years) meeting Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria of major depressive disorder from four hospitals in Southeast China. Patients were randomly assigned to 8-week oral treatment with 100,000 IU/week cholecalciferol (Vit D group) or a matching placebo (control group). The primary outcome was treatment response, defined as a 50% reduction in symptoms and change in scores of the Chinese version of Beck Depression Inventory (BDI) from baseline to 8 weeks. Relative risks of depression were estimated using multivariable logistic regression.

RESULTS

Finally, 120 patients were enrolled, including 56 test patients and 64 controls. After 8 weeks, the treatment response or BDI scores did not differ significantly between groups. Multivariate logistic regression showed that BDI scores were not significantly improved in the Vit D group after adjustment for age, time to first negative smear, or 25-hydroxyvitamin D level.

CONCLUSION

The use of high-dose Vit D3 supplementation may not be warranted for reducing depressive symptoms in the PTB population. Nevertheless, this finding should be validated by further large-scale studies according to different kinds of depression or Vit D receptor polymorphism genotype.

Efficacy of High-Dose Supplementation With Oral Vitamin D3 on Depressive Symptoms in Dialysis Patients With Vitamin D3 Insufficiency: A Prospective, Randomized, Double-Blind Study

Psychological problems are common among end-stage renal disease patients undergoing dialysis. We aim to evaluate whether high-dose vitamin D3 (VD3) supplementation has beneficial effects on depressive symptoms in dialysis patients. This prospective, randomized, and double-blind trial includes 746 dialysis patients with depression treated in 3 hospitals in Southeast China. Depression was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders criteria. Patients were randomly assigned to 52-week treatment of oral 50,000 IU/wk VD3 (cholecalciferol) (test group) or a placebo (control group). The presence of depressive symptoms was evaluated using the Chinese version of Beck Depression Inventory (BDI) II both before and after treatment. Sociodemographic data, clinical data, nutritional indexes, inflammatory biomarkers, and plasma VD3 concentrations were also determined. Finally, 726 patients completed the experiments, including 362 tested patients and 364 controls. After 52 weeks, the depressive symptoms were not significantly improved in the test group (mean BDI II scores changed from -1.1 ± 0.3 to -3.1 ± 0.6) versus the control group. Multivariable logistic regression showed BDI scores were not significantly improved in the test group versus the control group with adjustment for age, sex, comorbidity index, dialysis modality, or (OH)D levels (multivariable-adjusted mean change or MAMC [95% confidence interval (CI)], -2.3 [-2.48 to -1.83]) in the whole dialysis population. After stratification by depression types, the findings do support a significant relationship between the VD3 supplementation and the improvement in BDI II scores in dialysis patients with vascular depression (MAMC [95% CI], -4.4 [-5.08 to -2.76]), but the effect was not significant for major depressive disorders (MAMC [95% CI], -0.9 [-1.52 to -0.63]). The high-dose VD3 supplementation did not significantly reduce the depressive symptoms in our total dialysis population, but a beneficial effect on vascular depression was found, probably mainly based on the improvement of cardiovascular risk factors.

Building healthy bones throughout life: an evidence-informed strategy to prevent osteoporosis in Australia

Osteoporosis imposes a tremendous burden on Australia: 1.2 million Australians have osteoporosis and 6.3 million have osteopenia. In the 2007–08 financial year, 82 000 Australians suffered fragility fractures, of which > 17 000 were hip fractures. In the 2000–01 financial year, direct costs were estimated at $1.9 billion per year and an additional $5.6 billion on indirect costs. Osteoporosis was designated a National Health Priority Area in 2002; however, implementation of national plans has not yet matched the rhetoric in terms of urgency. Building healthy bones throughout life, the Osteoporosis Australia strategy to prevent osteoporosis throughout the life cycle, presents an evidence-informed set of recommendations for consumers, health care professionals and policymakers. The strategy was adopted by consensus at the Osteoporosis Australia Summit in Sydney, 20 October 2011. Primary objectives throughout the life cycle are: to maximise peak bone mass during childhood and adolescence to prevent premature bone loss and improve or maintain muscle mass, strength and functional capacity in healthy adults to prevent and treat osteoporosis in order to minimise the risk of suffering fragility fractures, and reduce falls risk, in older people. The recommendations focus on three affordable and important interventions — to ensure people have adequate calcium intake, vitamin D levels and appropriate physical activity throughout their lives. Recommendations relevant to all stages of life include: daily dietary calcium intakes should be consistent with Australian and New Zealand guidelines serum levels of vitamin D in the general population should be above 50nmol/L in winter or early spring for optimal bone health regular weight-bearing physical activity, muscle strengthening exercises and challenging balance/mobility activities should be conducted in a safe environment.

Validity of a self-administered diet history questionnaire for estimating vitamin D intakes of Japanese pregnant women

Maternal vitamin D status is important for fetal development and the prevention of pregnancy complications. Mothers require both sufficient intakes and skin production of this vitamin. We investigated the validity and test-retest reliability of a self-administered diet history questionnaire (DHQ) to establish a method of assessing vitamin D intakes of Japanese pregnant women, using a serum marker. A total of 245 healthy pregnant women in the second trimester, who were not taking vitamin D supplements, were recruited at a university hospital in Tokyo between June 2010 and July 2011. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured as an indicator of vitamin D status. To assess the test-retest reliability of the DHQ, 58 pregnant women completed it twice within a 4-5-week interval. Significant positive correlations between intakes and serum concentrations of vitamin D were found (r = 0.266 for daily intakes and r = 0.249 for energy-adjusted intakes). In the winter investigation in which the serum 25(OH)D concentrations were less likely to be affected by sunlight exposure, the correlation coefficients were 0.304 for both daily and energy-adjusted intakes. After excluding participants with pregnancy-associated nausea, the coefficients increased. The intraclass correlation coefficient between vitamin D intakes estimated from the two-time DHQ was 0.638. The DHQ provides an acceptable validity and reliability of the vitamin D intake of Japanese pregnant women. However, the data of women with nausea should be interpreted with caution. We believe that the DHQ is a useful questionnaire to grasp and improve vitamin D intakes during pregnancy.

Epidemiologic study of the C-3 epimer of 25-hydroxyvitamin D(3) in a population-based sample

BACKGROUND & AIMS

Vitamin D is associated with many health outcomes and the blood concentration of 25-hydroxyvitamin D [25(OH)D] is commonly measured in clinical practice. A C-3 epimer of this compound, 3-epi-25(OH)D3, has recently been detected in blood samples. Few clinical assays currently detect this epimer and its physiological function is unknown, as are the demographic, behavioral, and physiologic factors that may be correlated with it. We sought to determine the correlation between these factors and 3-epi-25(OH)D3.

METHODS

We conducted a cross-sectional population-based study of 303 non-Hispanic white participants in the Survey of the Health of Wisconsin. Serum 25(OH)D2, 25(OH)D3 and 3-epi-25(OH)D3 were measured by high-performance liquid chromatography tandem mass spectrometry. We measured vitamin D intake from foods and supplements via a food frequency questionnaire, sun exposure by spectrophotometry, waist circumference during a physical exam, and additional demographic and behavioral factors by questionnaire. We calculated the percent of 3-epi-25(OH)D3 out of the total 25(OH)D3.

RESULTS

Summer season (P = 0.009), higher alcohol intake (P = 0.007), and higher vitamin D intake from supplements (P = 0.0004), but not food (P = 0.20), were significantly associated with a higher percent of 3-epi-25(OH)D3 relative to the total 25(OH)D3, although these associations appear to be partially driven by individuals with low 3-epi-25(OH)D3. Moreover, the percent of 3-epi-25(OH)D3 was significantly correlated with the total 25(OH)D3 (r = 0.37, P < 0.0001).

CONCLUSIONS

We report findings from an epidemiologic study of 3-epi-25(OH)D3 and show that individuals with lower total 25(OH)D3 tend to have a lower percent of 3-epi-25(OH)D3 relative to the total. While this is the largest reported sample of adults with measured 3-epi-25(OH)D3, the sample size of 303 is relatively small and replication of our findings is necessary.

How important is vitamin D in preventing infections?

Interaction with the immune system is one of the most recently established nonclassic effects of vitamin D (VitD). For many years, this was considered to be limited to granulomatous diseases in which synthesis of active 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) or calcitriol is known to be increased. However, recent reports have supported a role for 1,25(OH)2D3 in promoting normal function of the innate and adaptive immune systems. Crucially, these effects seem to be mediated not only by the endocrine function of circulating calcitriol but also via paracrine (i.e., refers to effects to adjacent or nearby cells) and/or intracrine activity (i.e., refers to a hormone acting inside a cell) of 1,25(OH)2D3 from its precursor 25(OH)D3, the main circulating metabolite of VitD. The ability of this vitamin to influence human immune responsiveness seems to be highly dependent on the 25(OH)D3 status of individuals and may lead to aberrant response to infection or even to autoimmunity in those who are lacking VitD. The potential health significance of this has been underlined by increasing awareness of impaired status in populations across the globe. This review will examine the current understanding of how VitD status may modulate the responsiveness of the human immune system. Furthermore, we discuss how it may play a role in host resistance to common pathogens and how effective is its supplementation for treatment or prevention of infectious diseases in humans.

Determinants of vitamin D status in pregnant fair-skinned women in Sweden

Low maternal vitamin D status during pregnancy may have negative consequences for both mother and child. There are few studies of vitamin D status and its determinants in pregnant women living at northern latitudes. Thus, the present study investigates vitamin D status and its determinants during the third trimester of women living in Sweden (latitudes 57-58°N). A total of ninety-five fair-skinned pregnant women had blood taken between gestational weeks 35 and 37. The study included a 4 d food diary and questionnaires on dietary intake, supplement use, sun exposure, skin type, travels to southern latitudes and measure of BMI. Serum 25-hydroxyvitamin D (25(OH)D) was analysed using the chemiluminescence immunoassay. In the third trimester of pregnancy, mean serum concentration of 25(OH)D was 47.4 (sd 18.1) nmol/l (range 10-93 nmol/l). In total, 65% of women had serum 25(OH)D < 50 nmol/l and 17 % < 30 nmol/l. During the winter, 85% of the pregnant women had serum 25(OH)D < 50 nmol/l and 28 % < 30 nmol/l. The main determinants of vitamin D status were as follows: season; use of vitamin D supplements; travels to southern latitudes. Together, these explained 51% of the variation in 25(OH)D. In conclusion, during the winter, the majority of fair-skinned pregnant women had serum 25(OH)D < 50 nmol/l in their third trimester and more than every fourth woman < 30 nmol/l. Higher vitamin D intake may therefore be needed during the winter for fair-skinned pregnant women at northern latitudes to avoid vitamin D deficiency.

Vitamin D intake and season modify the effects of the GC and CYP2R1 genes on 25-hydroxyvitamin D concentrations

Vitamin D deficiency {defined by the blood concentration of 25-hydroxyvitamin D [25(OH)D]} has been associated with many adverse health outcomes. Genetic and nongenetic factors account for variation in 25(OH)D, but the role of interactions between these factors is unknown. To assess this, we examined 1204 women of European descent from the Carotenoids in Age-Related Eye Disease Study, an ancillary study of the Women's Health Initiative Observational Study. Twenty-nine single nucleotide polymorphisms (SNPs) in 4 genes, GC, CYP2R1, DHCR7, and CYP24A1, from recent meta-analyses of 25(OH)D genome-wide association studies were genotyped. Associations between these SNPs and 25(OH)D were tested using generalized linear regression under an additive genetic model adjusted for age, blood draw month, and ancestry. Results were stratified by season of blood draw and, separately, vitamin D intake for the 6 SNPs showing a significant association with 25(OH)D at the P < 0.01 level. Two nonsynonymous SNPs in GC and 4 SNPs in CYP2R1 were strongly associated with 25(OH)D in individuals whose blood was drawn in summer (P ≤ 0.002) but not winter months and, independently, in individuals with vitamin D intakes ≥400 (P ≤ 0.004) but not <400 IU/d (10 μg/d). This effect modification, if confirmed, has important implications for the design of genetic studies for all health outcomes and for public health recommendations and clinical practice guidelines regarding the achievement of adequate vitamin D status.

The role of photolabile dermal nitric oxide derivates in ultraviolet radiation (UVR)-induced cell death

Human skin is exposed to solar ultraviolet radiation comprising UVB (280–315 nm) and UVA (315–400 nm) on a daily basis. Within the last two decades, the molecular and cellular response to UVA/UVB and the possible effects on human health have been investigated extensively. It is generally accepted that the mutagenic and carcinogenic properties of UVB is due to the direct interaction with DNA. On the other hand, by interaction with non-DNA chromophores as endogenous photosensitizers, UVA induces formation of reactive oxygen species (ROS), which play a pivotal role as mediators of UVA-induced injuries in human skin. This review gives a short overview about relevant findings concerning the molecular mechanisms underlying UVA/UVB-induced cell death. Furthermore, we will highlight the potential role of cutaneous antioxidants and photolabile nitric oxide derivates (NODs) in skin physiology. UVA-induced decomposition of the NODs, like nitrite, leads not only to non-enzymatic formation of nitric oxide (NO), but also to toxic reactive nitrogen species (RNS), like peroxynitrite. Whereas under antioxidative conditions the generation of protective amounts of NO is favored, under oxidative conditions, less injurious reactive nitrogen species are generated, which may enhance UVA-induced cell death.

Vitamin D in the maternal-fetal-neonatal interface: clinical implications and requirements for supplementation

Identification of the current evidence regarding the pathophysiological and clinical facets of vitamin D in the maternal-fetal-neonatal interface is of value because of the significance of the vitamin D endocrine system in human health and high prevalence of vitamin D deficiency in mothers and their infants. Although many questions have still not been answered by the existing literature, we found evidence that: (i) during pregnancy vitamin D participates in fetal skeletal mineralization and growth, (ii) neonatal vitamin D levels are dependent on the maternal vitamin D status at delivery, (iii) a vitamin D sufficient status at birth may decrease the risk for the development of asthma and type 1 diabetes mellitus in later life, (iv) recommendations for maintaining serum 25-hydroxyvitamin D [25(OH)D] levels ≥32 ng/mL to avoid secondary hyperparathyroidism in adults have not been applied to mothers and their infants, (v) American Academy of Pediatrics recommended supplementation of 400 IU of vitamin D per day is sufficient only for infants who are born with normal vitamin D levels and (vii) supplementation of lactating mothers with high doses of vitamin D (4000 IU/d) allows the achievement of optimal 25(OH)D concentrations (>32 ng/mL) in the maternal and infant serum without any risk of hypervitaminosis D in the mother. We believe that inconsistency in the recognition of sufficient levels of vitamin D in mothers and their infants affects the identification of adequate doses for vitamin D supplementation during pregnancy, lactation and infancy.

High prevalence of vitamin D deficiency in pregnant women: a national cross-sectional survey

An increasing number of studies suggest that vitamin D deficiency during pregnancy is associated with multiple adverse health outcomes in mothers, neonates and children. There are no representative country data available on vitamin D status of pregnant women in Europe. The aim of this study was to estimate the prevalence of vitamin D deficiency among Belgian pregnant women and to assess the determinants of vitamin D status in the first and third trimester of pregnancy. The women were selected via a multi-stage proportionate-to-size sampling design. Blood samples were collected and a questionnaire was completed face-to-face. 55 obstetric clinics were randomly selected and 1311 pregnant women participated in the study. The median serum 25-hydroxyvitamin D [25-(OH)D] concentration was significantly lower in the first trimester (20.4 ng/ml) than in third trimester (22.7 ng/ml). Of all women, 74.1% (95%CI = 71.8–76.5%) were vitamin D insufficient (25-(OH)D <30 ng/ml), 44.6% (95%CI = 41.9–47.3%) were vitamin D deficient (25-(OH)D <20 ng/ml), while 12.1% (95%CI = 10.3–13.8%) were severely vitamin D deficient (25-(OH)D <10 ng/ml). Of all women included, 62.0% reported taking vitamin D-containing multivitamins, of which only 24.2% started taking those before pregnancy. The risk of vitamin D deficiency (25-(OH)D <20 ng/ml) was significantly higher for less educated women and women who reported not going on holidays to sunny climates. The risk of severe vitamin D deficiency (25-(OH)D <10 ng/ml) decreased for women who reported alcohol consumption during pregnancy, decreased with more frequent use of sunscreen lotion and increased for smokers and women who reported preference for shadow. In conclusion, vitamin D deficiency is highly prevalent among pregnant women in Belgium and this raises concerns about the health consequences for the mother and the offspring. A targeted screening strategy to detect and treat women at high risk of severe vitamin D deficiency is needed in Belgium and in Europe.

1α,25-Dihydroxyvitamin D3 modulates the interaction between immune and colon cancer cells

Following observations indicating the existence of a relationship between immune and cancer cells in the course of tumor development, it was the aim of the study to establish the role of 1α,25-dihydroxyvitamin D3 (vit. D) in the functional equilibrium between cells from two human colon carcinoma lines-induced cytokine production by peripheral blood mononuclear cells (PBMC). PBMC were incubated with HT-29 and RKO human colon cancer cells with and without vit. D at final concentrations of 10⁻⁸, 10⁻⁷ or 10⁻⁶ M. The production of the cytokines TNF-α, IL-6 and IL-10, as well as the effect of the vitamin on tumor cell proliferation were evaluated. Incubation of PBMC with either HT-29 or RKO cells caused a significant stimulation of both pro- and anti-inflammatory cytokine generation. Addition of vit. D to the incubation mixture containing PBMC and cells of both colon carcinoma lines caused a marked inhibition of the generation of the pro-inflammatory cytokines TNF-α and IL-6 and to a lesser extent-of the IL-10. Vit. D did not affect the proliferation of the cancer cells. The results indicate the existence of a functional "dialog" between immune and cancer cells expressed by an alteration of their capacity for cytokine production and support the role of inflammation in carcinogenesis. The ability of vit. D to attenuate production of the pro-inflammatory cytokines when added to the incubation mixture containing PBMC and cancer cells endorses observations as for the beneficial role of the vitamin in suppressing inflammation with subsequent colon cancer prevention.

Is vitamin D status relevant to metabolic syndrome?

Review of the evidence on hypovitaminosis D as a risk factor for metabolic syndrome and its sequelae, T2DM and CVD, suggests long-term vitamin D repletion could reduce these risks. There is mechanistic evidence for protective effects for MetS and the balance of evidence, (cross-sectional and prospective), supports this postulate. Much of the data so far available from randomized controlled trials is weakened by inadequate power, low vitamin D dosages, starting supplementation too late in life or after MetS disorders have developed or, most importantly, by non-inclusion of many recognizable confounders. On balance, therefore, maintenance of US 2010 recommended intakes for bone protection has the potential to prove protective for MetS. Supplementation has been shown to increase survival in patients with cardiac disorders; whether higher doses would provide useful protection for apparently healthy people in the general population awaits the outcomes of ongoing randomized-controlled trials that, it is hoped, will prove or disprove causality for hypovitaminosis D in MetS and its long-term ill-effects.

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.