Vitamin D3 and brain development

Vitamin D, effects on brain development, adult brain function and the links between low levels of vitamin D and neuropsychiatric disease

Increasingly vitamin D deficiency is being associated with a number of psychiatric conditions. In particular for disorders with a developmental basis, such as autistic spectrum disorder and schizophrenia the neurobiological plausibility of this association is strengthened by the preclinical data indicating vitamin D deficiency in early life affects neuronal differentiation, axonal connectivity, dopamine ontogeny and brain structure and function. More recently epidemiological associations have been made between low vitamin D and psychiatric disorders not typically associated with abnormalities in brain development such as depression and Alzheimer's disease. Once again the preclinical findings revealing that vitamin D can regulate catecholamine levels and protect against specific Alzheimer-like pathology increase the plausibility of this link. In this review we have attempted to integrate this clinical epidemiology with potential vitamin D-mediated basic mechanisms. Throughout the review we have highlighted areas where we think future research should focus.

Vitamin D concentration and lateral cerebral ventricle volume in older adults

SCOPE

Vitamin D deficiency is associated with an enlargement of the lateral cerebral ventricles in rodents. The effect of low serum 25-hydroxyvitamin D (25OHD) on lateral cerebral ventricle volume has not been studied yet in humans. The purpose of this cross-sectional study was to determine whether vitamin D deficiency was associated with greater lateral cerebral ventricle volume in older adults.

METHODS AND RESULTS

Ninety-two Caucasian community-dwellers with no clinical hydrocephalus (mean, 72.2 ± 6.2 years; 46.7% female) were divided into two groups according to serum 25OHD concentration (deficiency ≤ 50 nmol/L; normal > 50 nmol/L). Cerebral ventricular volume was quantified using semi-automated software from three-dimensional T1-weighted MRI. Age, gender, body mass index, blood pressure, education level, Mini-Mental State Examination, white matter lesions, and serum calcium concentrations were used as covariates. There was an inverse linear association between 25OHD concentration and ventricular volume (p = 0.049). Compared to individuals with normal 25OHD, those with 25OHD deficiency (n = 33) had 28% larger lateral ventricles (46.9 ± 26.8 mL versus 36.6 ± 16.4 mL, p = 0.026). Vitamin D deficiency was associated with an increase in ventricular volume (adjustedβ = 16.55, p = 0.023). The ventricular enlargement involved ventricle bodies (p = 0.025) but not temporal horns (p = 0.112).

CONCLUSION

Serum 25OHD deficiency was associated with larger lateral cerebral ventricles. These findings provide a scientific base for vitamin D replacement trials.

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.

Vitamin D mitigates age-related cognitive decline through the modulation of pro-inflammatory state and decrease in amyloid burden

Background

Increasing evidence shows an association between the use of vitamin D and improvement in age-related cognitive decline. In this study, we investigated the possible mechanisms involved in the neuroprotective effects of vitamin D on age-related brain changes and cognitive function.

Methods

Male F344 rats aged 20 months (old) and 6 months (young) were used and randomly assigned to either vitamin D supplementation or no supplementation (control). A total of n = 39 rats were used in the study. Rats were individually housed and the supplementation group received a subcutaneous injection of vitamin D (1, α25-dihydroxyvitamin D3) 42 I.U./Kg for 21 days. Control animals received equal volume of normal saline. Behavioral testing in water maze and spontaneous object recognition tasks started on day 14. Levels of interleukin (IL)-1β and IL-10 were quantified to assess inflammatory state. Also, beta amyloid (Aβ) clearance and Aβ load were measured.

Results

Our results show that: (1) aged rats demonstrated significant learning and memory impairment overall compared to younger animals. However, the age-related decline in learning and memory was ameliorated by the supplementation of vitamin D. No vitamin D effect on learning and memory was seen in the young animals; 2) the pro-inflammatory cytokine IL-1β is significantly increased while the anti-inflammatory cytokine IL-10 is significantly decreased in the aged rats compared to the young animals; but this age-related change in inflammatory state was mitigated by vitamin D supplementation. No effects of vitamin D were seen on the IL-1β and IL-10 expression in the young rats; (3) vitamin D increased Aβ clearance and decreased amyloid burden in the aged rats while no significant difference was seen between the young animal groups.

Conclusions

Our data suggest that vitamin D supplementation modulated age-related increase in pro-inflammatory state and amyloid burden. It is possible that these effects of vitamin D mediated the decrease memory impairment seen in the aged rats making it a useful therapeutic option to alleviate the effects of aging on cognitive function.

Effects of antipsychotics on dentate gyrus stem cell proliferation and survival in animal models: a critical update

Schizophrenia is a complex psychiatric disorder. Although a number of different hypotheses have been developed to explain its aetiopathogenesis, we are far from understanding it. There is clinical and experimental evidence indicating that neurodevelopmental factors play a major role. Disturbances in neurodevelopment might result in alterations of neuroanatomy and neurochemistry, leading to the typical symptoms observed in schizophrenia. The present paper will critically address the neurodevelopmental models underlying schizophrenia by discussing the effects of typical and atypical antipsychotics in animal models. We will specifically discuss the vitamin D deficiency model, the poly I:C model, the ketamine model, and the postnatal ventral hippocampal lesion model, all of which reflect core neurodevelopmental issues underlying schizophrenia onset.

Vitamin D-insufficiency: An estimate of the situation in Germany

Background: Vitamin D insufficiency is increasingly recognized as an important risk factor in the pathogenesis of falls and fractures and may increase the risk of other diseases. The aim of this study was to obtain information about the vitamin D supply from a representative cohort of the German population.

 

Methods: 264 General practitioners participated in the DeViD-Trial (D-Vitamin in Deutschland) by taking blood samples from their consenting daily ambulant patients regardless of the actual reason for consultation. In these blood samples vitamin D [25(OH)D] and other related parameters were measured at a central laboratory. The patients filled in a simple questionnaire (i.e., age, sex, etc.). The trial was performed between February 26 and May 25, 2007.

Results: Laboratory and personal data were documented for 1,343 individuals (615 men, 728 women). The age distribution ranged from 20 to 99 y, the mean age of the whole cohort was 57.6 y (men 58.2, women 57.2). The mean 25-OH-D-value for the whole cohort was 16.2 ng/ml (range: 6.0 to 66.8, median 14.1 ng/ml). Ten percent of the patients had 25(OH)D-values below 7 ng/ml, 65% below 20 ng/ml and 92% showed values below 30 ng/ml.

In the more recent literature, 25(OH)D values below 30 ng/ml are regarded as sub-optimal for bone, muscle and general health. Correspondingly it can be stated that in this representative population there is a high prevalence of moderate to severe vitamin D-insufficiency regardless of young or old age

[Hungarian consensus regarding the role of vitamin D in the prevention and treatment of diseases]

The metabolism of vitamin D is unique in the human body and its diverse effects are present in almost every organ. Vitamin D deficiency is one of the most prominent health issues in the civilized world. For the solution of this concern an extensive collaboration is imperative. Recognizing this necessity the most prominent Hungarian medical associations fighting with the effects of vitamin D deficiency worked out a collective consensus on the importance, diagnosis, prevention and suggested therapy of vitamin D deficiency. Along with the clinical guidelines of the different associations, the result of this consensus could serve as guidance for the practicing doctors in the prevention and therapy of vitamin D deficiency. In addition the consensus aims to direct the attention of decision-makers and the general public on the significance of this issue.

The neurodevelopmental hypothesis of schizophrenia: convergent clues from epidemiology and neuropathology

The neurodevelopmental hypothesis of schizophrenia suggests that the disruption of early brain development increases the risk of later developing schizophrenia. This hypothesis focuses attention on critical periods of early brain development. From an epidemiologic perspective, various prenatal and perinatal risk factors have been linked to schizophrenia, including exposures related to infection, nutrition, and obstetric complications. From a genetic perspective, candidate genes have also been linked to altered brain development. In recent decades evidence from neuropathology has provided support for the neurodevelopmental hypothesis. Animal models involving early life exposures have been linked to changes in these same brain systems, providing convergent evidence for this long-standing hypothesis.

Prenatal vitamin D deficiency induces an early and more severe experimental autoimmune encephalomyelitis in the second generation

In a previous study, we demonstrated that mouse adult F(1) offspring, exposed to a vitamin D deficiency during pregnancy, developed a less severe and delayed Experimental Autoimmune Encephalomyelitis (EAE), when compared with control offspring. We then wondered whether a similar response was observed in the subsequent generation. To answer this question, we assessed F(2) females whose F(1) parents (males or females) were vitamin D-deprived when developing in the uterus of F(0) females. Unexpectedly, we observed that the vitamin D deficiency affecting the F(0) pregnant mice induced a precocious and more severe EAE in the F(2) generation. This paradoxical finding led us to assess its implications for the epidemiology of Multiple Sclerosis (MS) in humans. Using the REFGENSEP database for MS trios (the patient and his/her parents), we collected the parents' dates of birth and assessed a potential season of birth effect that could potentially be indicative of the vitamin D status of the pregnant grandmothers. A trend for a reduced number of births in the Fall for the parents of MS patients was observed but statistical significance was not reached. Further well powered studies are warranted to validate the latter finding.

The role of vitamin D in pregnancy and lactation: emerging concepts

Pregnancy is a critical time in the lifecycle of a woman where she is responsible not only for her own well-being, but also that of her developing fetus, a process that continues during lactation. Until recently, the impact of vitamin D status during this period had not been fully appreciated. Data regarding the importance of vitamin D in health have emerged to challenge traditional dogma, and suggest that vitamin D - through its effect on immune function and surveillance - plays a role beyond calcium and bone metabolism on the health status of both the mother and her fetus. Following birth, this process persists; the lactating mother continues to be the main source of vitamin D for her infant. Thus, during both pregnancy and lactation, maternal deficiency predicts fetal and infant deficiency; the significance of this is just beginning to be understood and will be highlighted in this review.

Possibility of a new anti-alzheimer's disease pharmaceutical composition combining memantine and vitamin D

Alzheimer's disease (AD) is the leading cause of dementia. In addition to a decrease in brain cholinergic activity, AD is also marked by glutamatergic excitotoxicity that results in neuronal death, characterized clinically by a loss of learning and memory abilities. The currently available drugs for symptomatic treatment of AD (i.e. memantine and acetylcholinesterase inhibitors) only temporarily slow down the natural history of the disease process. Among them, memantine is the only one that acts as a non-competitive low-affinity modulator of N-methyl-D-aspartate (NMDA) receptors. Memantine's modulation of NMDA receptors has been reported to prevent the neuronal necrosis induced by glutamatergic calcium neurotoxicity, but not the neuronal apoptosis resulting from oxidative stress. This observation calls for new drug regimen strategies based on memantine combined with molecules having antioxidant effects, in order to create a multi-target therapy to increase neuronal protection and prevent AD progression. We wish to highlight that vitamin D is a secosteroid hormone that is suggested to have neuroprotective effects that include regulation of neuronal calcium homeostasis, as well as antioxidant, neurotrophic and anti-inflammatory properties. The combination of memantine plus vitamin D may provide, in one treatment, enhanced protection against several degenerative processes linked to AD. Based on the present rationale, a clinical trial testing this hypothesis is currently in recruitment (AD-IDEA trial; ClinicalTrials.gov identifier: NCT01409694). This new pharmaceutical composition may provide an effective solution to the problem of neuronal death and cognitive decline in AD.

Maternal vitamin D deficiency delays glomerular maturity in F1 and F2 offspring

Background

There is a high prevalence of vitamin D insufficiency in women of reproductive age.

Methods

This work studied the first two generations of offspring (F1 and F2) of Swiss mice from mothers fed one of two diets: SC (standard chow) or VitD- (vitamin D-deficient). Functional and developmental kidney measurements were taken.

Results

The first two generations of the VitD- group had higher blood pressure at 6 months of age than the offspring of the SC group as well as an increase in renin and AT1r expression. However, at all ages, both F1 and F2 VitD- mice had shorter glomerular diameters, and diet played a significant role in the total variation. Both the F1 and F2 generations of the VitD- group had more immature glomeruli than offspring from the SC group. Immature glomeruli begin to disappear at 10 days, but at this age, F1-VitD- mice had more immature and mature glomeruli than F1-SC mice. At 6 months of age, F1-VitD- mice exhibited more glomeruli, while F2-VitD- mice exhibited the same number of glomeruli as F2-SC mice, but fewer glomeruli compared to the F1-VitD group. Both diet and generation account for the total variation in the number of glomeruli. Decreases in urine output and podocin expression and increases in urea and creatinine in the urine were observed in F1 offspring.

Conclusion

These findings demonstrate that maternal vitamin D deficiency accompanies changes in the renal expression of important factors that may retard the maturation of glomeruli by extending the period of nephrogenesis.

Effect of vitamin D deficiency during pregnancy on offspring bone structure, composition and quality in later life

During foetal development, calcium requirements are met as a consequence of maternal adaptations independent of vitamin D status. In contrast, after birth, dependency on vitamin D appears necessary for calcium metabolism and skeletal health. We used a rodent model (Sprague-Dawley rats), to determine if maternal vitamin D deficiency during pregnancy had a deleterious effect on bone structure at birth. Vitamin D deplete females were maintained under deplete conditions until birth of the pups, whereupon all dams were fed a vitamin D replete diet. Offspring were harvested at birth, and 140 days of age. Bones were analyzed using micro-computed tomography and strength tested to study differences in bone structure, density and strength and subjected to elemental analysis using plasma mass spectrometry to determine strontium, barium and calcium contents. Offspring from deplete mothers displayed altered trabecular parameters in the femur at birth and 140 days of age. In addition, at 140 days of age there was evidence of premature mineralization of the secondary ossification centre of the femoral head. Elemental analysis showed increased strontium uptake in the femur of the developmentally vitamin D-deficient offspring. Vitamin D depletion during development in the offspring may have a long-lasting effect, despite repletion of vitamin D from birth. This may have consequences for human health given the low vitamin D levels seen during pregnancy and current lifestyle of sun avoidance due to the risk of skin cancer.

Serum 25-hydroxyvitamin D3 and D2 and non-clinical psychotic experiences in childhood

Objective

Non-clinical psychotic experiences are common and distressing. It has been hypothesized that early life vitamin D deficiency may be a risk factor for psychosis-related outcomes, but it is not known if circulating concentrations of 25-hydroxyvitamin D (25(OH)D) during childhood are associated with psychosis-related outcomes or whether the two different forms of 25(OH)D, (25(OH)D₃ and 25(OH)D₂, have similar associations with psychosis-related outcomes.

Methods

We investigated the association between serum 25(OH)D₃ and 25(OH)D₂ concentrations and psychotic experiences in a prospective birth cohort study. Serum 25(OH)D₃ and 25(OH)D₂ concentrations were measured at mean age 9.8 years and psychotic experiences assessed at mean age 12.8 years by a psychologist (N = 3182).

Results

Higher 25(OH)D₃ concentrations were associated with lower risk of definite psychotic experiences (adjusted odds ratio: OR (95% confidence interval: CI) 0.85 (0.75–0.95)). Higher concentrations of 25(OH)D₂ were associated with higher risk of suspected and definite psychotic experiences (adjusted odds ratio: OR (95% confidence interval: CI) 1.26 (1.11, 1.43)). Higher 25(OD)D₂ concentrations were also weakly associated with definite psychotic experiences (adjusted OR (95% CI) 1.17 (0.96, 1.43), though with wide confidence intervals including the null value.

Conclusions

Our findings of an inverse association of 25(OH)D₃ with definite psychotic experiences is consistent with the hypothesis that vitamin D may protect against psychosis-related outcomes.

Cancer-related stress and complementary and alternative medicine: a review

A cancer diagnosis elicits strong psychophysiological reactions that characterize stress. Stress is experienced by all patients but is usually not discussed during patient-healthcare professional interaction; thus underdiagnosed, very few are referred to support services. The prevalence of CAM use in patients with history of cancer is growing. The purpose of the paper is to review the aspects of cancer-related stress and interventions of commonly used complementary and alternative techniques/products for amelioration of cancer-related stress. Feasibility of intervention of several CAM techniques and products commonly used by cancer patients and survivors has been established in some cancer populations. Efficacy of some CAM techniques and products in reducing stress has been documented as well as stress-related symptoms in patients with cancer such as mindfulness-based stress reduction, yoga, Tai Chi Chuan, acupuncture, energy-based techniques, and physical activity. Much of the research limitations include small study samples and variety of intervention length and content. Efficacy and safety of many CAM techniques and some herbs and vitamin B and D supplements need to be confirmed in further studies using scientific methodology. Several complementary and alternative medicine therapies could be integrated into standard cancer care to ameliorate cancer-related stress.

The association of 25-hydroxyvitamin D3 and D2 with behavioural problems in childhood

BACKGROUND

Higher serum concentrations of 25-hydroxyvitamin D (25(OH)D), an indicator of vitamin D synthesis and intake, have been associated with better mental health and cognitive function. Concentrations of 1,25-dihydroxyvitamin D(3) (the active vitamin D(3) metabolite) have been associated with openness and extrovert behaviour, but 25(OH)D concentrations have not been associated with behavioural problems in humans.

METHODS

We investigated the prospective association between the different forms of 25(OH)D - 25(OH)D(3) and 25(OH)D(2)- and childhood behavioural problems in Avon Longitudinal Study of Parents and Children (ALSPAC). Serum 25(OH)D(3) and 25(OH)D(2) concentrations were assessed at mean age 9.9 years. Incident behavioural problems were assessed with Strengths and Difficulties Questionnaire (SDQ; emotional symptoms, conduct problems, hyperactivity-inattention problems, peer relationship problems and pro-social behaviour subscales and total difficulties score) at mean age 11.7. Sample sizes varied between 2413-2666 depending on the outcome.

RESULTS

Higher 25(OH)D(3) concentrations were weakly associated with lower risk of prosocial problems (fully adjusted odds ratio: OR (95% confidence interval: CI) 0.85 (0.74, 0.98)). Serum 25(OH)D(3) or 25(OH)D(2) concentrations were not associated with other subscales of SDQ or total difficulties score after adjusting for concfounders and other measured analytes related to vitamin D.

CONCLUSIONS

Our findings do not support the hypothesis that 25-hydroxyvitamin D status in childhood has important influences on behavioural traits in humans.

Benefits of docosahexaenoic acid, folic acid, vitamin D and iodine on foetal and infant brain development and function following maternal supplementation during pregnancy and lactation

Scientific literature is increasingly reporting on dietary deficiencies in many populations of some nutrients critical for foetal and infant brain development and function.

PURPOSE

To highlight the potential benefits of maternal supplementation with docosahexaenoic acid (DHA) and other important complimentary nutrients, including vitamin D, folic acid and iodine during pregnancy and/or breast feeding for foetal and/or infant brain development and/or function.

METHODS

English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies were obtained through searches on MEDLINE and the Cochrane Register of Controlled Trials from January 2000 through to February 2012 and reference lists of retrieved articles. Reports were selected if they included benefits and harms of maternal supplementation of DHA, vitamin D, folic acid or iodine supplementation during pregnancy and/or lactation.

RESULTS

Maternal DHA intake during pregnancy and/or lactation can prolong high risk pregnancies, increase birth weight, head circumference and birth length, and can enhance visual acuity, hand and eye co-ordination, attention, problem solving and information processing. Vitamin D helps maintain pregnancy and promotes normal skeletal and brain development. Folic acid is necessary for normal foetal spine, brain and skull development. Iodine is essential for thyroid hormone production necessary for normal brain and nervous system development during gestation that impacts childhood function.

CONCLUSION

Maternal supplementation within recommended safe intakes in populations with dietary deficiencies may prevent many brain and central nervous system malfunctions and even enhance brain development and function in their offspring.

Neonatal seizures: controversies and challenges in translating new therapies from the lab to the isolette

Neonatal seizures have unique properties that have proved challenging for both clinicians and basic science researchers. Clinical therapies aimed at neonatal seizures have proven only partially effective and new therapies are slow to develop. This article will discuss neonatal seizures within the framework of the barriers that exist to the development of new therapies, and the challenges inherent in bringing new therapies from the bench to the bedside. With the European Union and USA creating national collaborative project infrastructure, improved collaborative resources should advance clinical research on urgently needed new therapies for this disorder.

Vitamin D deficiency exacerbates experimental stroke injury and dysregulates ischemia-induced inflammation in adult rats

Vitamin D deficiency (VDD) is widespread and considered a risk factor for cardiovascular disease and stroke. Low vitamin D levels are predictive for stroke and more fatal strokes in humans, whereas vitamin D supplements are associated with decreased risk of all-cause mortality. Because VDD occurs with other comorbid conditions that are also independent risk factors for stroke, this study examined the specific effect of VDD on stroke severity in rats. Adult female rats were fed control or VDD diet for 8 wk and were subject to middle cerebral artery occlusion thereafter. The VDD diet reduced circulating vitamin D levels to one fifth (22%) of that observed in rats fed control chow. Cortical and striatal infarct volumes in animals fed VDD diet were significantly larger, and sensorimotor behavioral testing indicated that VDD animals had more severe poststroke behavioral impairment than controls. VDD animals were also found to have significantly lower levels of the neuroprotective hormone IGF-I in plasma and the ischemic hemisphere. Cytokine analysis indicated that VDD significantly reduced IL-1α, IL-1β, IL-2, IL-4, IFN-γ, and IL-10 expression in ischemic brain tissue. However, ischemia-induced IL-6 up-regulation was significantly higher in VDD animals. In a separate experiment, the therapeutic potential of acute vitamin D treatments was evaluated, where animals received vitamin D injections 4 h after stroke and every 24 h thereafter. Acute vitamin D treatment did not improve infarct volume or behavioral performance. Our data indicate that VDD exacerbates stroke severity, involving both a dysregulation of the inflammatory response as well as suppression of known neuroprotectants such as IGF-I.

Management of inflammatory bowel disease with vitamin D: beyond bone health

A relationship between vitamin D and several disorders, including Crohn's disease (CD), has recently been proposed. Vitamin D appears to have several important actions beyond the maintenance of bone health, including various effects on the immune system. Vitamin D deficiency has been implicated in the development of CD, and its analogues may have a role in the treatment of CD. Current research also suggests a role for vitamin D in counteracting some IBD-specific complications, including osteopenia, colorectal neoplasia, and depression. There remains a need for prospective studies to further delineate these relationships. Given current evidence and the apparent safety of vitamin D supplementation, it appears reasonable to screen for and treat vitamin D deficiency in patients with IBD.

Attentional processing in C57BL/6J mice exposed to developmental vitamin D deficiency

Epidemiological evidence suggests that Developmental Vitamin D (DVD) deficiency is associated with an increased risk of schizophrenia. DVD deficiency in mice is associated with altered behaviour, however there has been no detailed investigation of cognitive behaviours in DVD-deficient mice. The aim of this study was to determine the effect of DVD deficiency on a range of cognitive tasks assessing attentional processing in C57BL/6J mice. DVD deficiency was established by feeding female C57BL/6J mice a vitamin D-deficient diet from four weeks of age. After six weeks on the diet, vitamin D-deficient and control females were mated with vitamin D-normal males and upon birth of the pups, all dams were returned to a diet containing vitamin D. The adult offspring were tested on a range of cognitive behavioural tests, including the five-choice serial reaction task (5C-SRT) and five-choice continuous performance test (5C-CPT), as well as latent inhibition using a fear conditioning paradigm. DVD deficiency was not associated with altered attentional performance on the 5C-SRT. In the 5C-CPT DVD-deficient male mice exhibited an impairment in inhibiting repetitive responses by making more perseverative responses, with no changes in premature or false alarm responding. DVD deficiency did not affect the acquisition or retention of cued fear conditioning, nor did it affect the expression of latent inhibition using a fear conditioning paradigm. DVD-deficient mice exhibited no major impairments in any of the cognitive domains tested. However, impairments in perseverative responding in DVD-deficient mice may indicate that these animals have specific alterations in systems governing compulsive or reward-seeking behaviour.

Association of serum 25-hydroxyvitamin D₃ and D₂ with academic performance in childhood: findings from a prospective birth cohort

Background

Higher total serum 25-hydroxyvitamin D (25(OH)D) concentrations have been associated with better cognitive function mainly in cross-sectional studies in adults. It is unknown if the associations of different forms of 25(OH)D (25(OH)D₃ and 25(OH)D₂) are similar.

Methods

Prospective cohort study (n=3171) with serum 25(OH)D₃ and 25(OH)D₂ concentrations measured at mean age of 9.8 years and academic performance at age 13–14 years (total scores in English, mathematics and science) and 15–16 years (performance in General Certificates of Education examinations).

Results

Serum 25(OH)D₃ concentrations were not associated with any educational outcomes. Higher 25(OH)D₂ concentrations were associated with worse performance in English at age 13–14 years (adjusted SD change per doubling in 25(OH)D₂ (95% CI) −0.05 (−0.08 to −0.01)) and with worse academic performance at age 15–16 years (adjusted OR for obtaining ≥5 A*–C grades (95% CI) 0.91 (0.82 to 1.00)).

Conclusion

The null findings with 25(OH)D₃ are in line with two previous cross-sectional studies in children. It is possible that the positive association of 25(OH)D with cognitive function seen in adults does not emerge until later in life or that the results from previous cross-sectional adult studies are due to reverse causality. The unexpected inverse association of 25(OH)D₂ with academic performance requires replication in further studies. Taken together, our findings do not support suggestions that children should have controlled exposure to sunlight, or vitamin D supplements, in order to increase academic performance.

Developmental vitamin D deficiency alters MK-801-induced behaviours in adult offspring

RATIONALE

Developmental vitamin D (DVD) deficiency is a candidate risk factor for developing schizophrenia in humans. In rodents DVD deficiency induces subtle changes in the way the brain develops. This early developmental insult leads to select behavioural changes in the adult, such as an enhanced response to amphetamine-induced locomotion in female DVD-deficient rats but not in male DVD-deficient rats and an enhanced locomotor response to the N-methyl-D: -aspartate (NMDA) receptor antagonist, MK-801, in male DVD-deficient rats. However, the response to MK-801-induced locomotion in female DVD-deficient rats is unknown. Therefore, the aim of the current study was to further examine this behavioural finding in male and female rats and assess NMDA receptor density.

METHODS

DVD-deficient Sprague Dawley rats were assessed for locomotion, ataxia, acoustic startle response (ASR) and prepulse inhibition (PPI) of the ASR to multiple doses of MK-801. The NMDA receptor density in relevant brain regions was assessed in a drug-naive cohort.

RESULTS

DVD deficiency increased locomotion in response to MK-801 in both sexes. DVD-deficient rats also showed an enhanced ASR compared with control rats, but PPI was normal. Moreover, DVD deficiency decreased NMDA receptor density in the caudate putamen of both sexes.

CONCLUSIONS

These results suggest that a transient prenatal vitamin D deficiency has a long-lasting effect on NMDA-mediated signalling in the rodent brain and may be a plausible candidate risk factor for schizophrenia and other neuropsychiatric disorders.

Maternal serum vitamin D levels during pregnancy and offspring neurocognitive development

OBJECTIVES

To determine the association between maternal serum 25(OH)-vitamin D concentrations during a critical window of fetal neurodevelopment and behavioral, emotional, and language outcomes of offspring.

METHODS

Serum 25(OH)-vitamin D concentrations of 743 Caucasian women in Perth, Western Australia (32°S) were measured at 18 weeks pregnancy and grouped into quartiles. Offspring behavior was measured with the Child Behavior Checklist at 2, 5, 8, 10, 14, and 17 years of age (n range = 412-652). Receptive language was assessed with the Peabody Picture Vocabulary Test-Revised at ages 5 (n = 534) and 10 (n = 474) years. Raw scores were converted to standardized scores, incorporating cutoffs for clinically significant levels of difficulty.

RESULTS

χ(2) analyses revealed no significant associations between maternal 25(OH)-vitamin D serum quartiles and offspring behavioral/emotional problems at any age. In contrast, there were significant linear trends between quartiles of maternal vitamin D levels and language impairment at 5 and 10 years of age. Multivariate regression analyses, incorporating a range of confounding variables, found that the risk of women with vitamin D insufficiency (≤46 nmol/L) during pregnancy having a child with clinically significant language difficulties was increased close to twofold compared with women with vitamin D levels >70 nmol/L.

CONCLUSIONS

Maternal vitamin D insufficiency during pregnancy is significantly associated with offspring language impairment. Maternal vitamin D supplementation during pregnancy may reduce the risk of developmental language difficulties among their children.

Vitamin D and its role during pregnancy in attaining optimal health of mother and fetus

Despite its discovery a hundred years ago, vitamin D has emerged as one of the most controversial nutrients and prohormones of the 21st century. Its role in calcium metabolism and bone health is undisputed but its role in immune function and long-term health is debated. There are clear indicators from in vitro and animal in vivo studies that point to vitamin D's indisputable role in both innate and adaptive immunity; however, the translation of these findings to clinical practice, including the care of the pregnant woman, has not occurred. Until recently, there has been a paucity of data from randomized controlled trials to establish clear cut beneficial effects of vitamin D supplementation during pregnancy. An overview of vitamin metabolism, states of deficiency, and the results of recent clinical trials conducted in the U.S. are presented with an emphasis on what is known and what questions remain to be answered.

Schizophrenia: do all roads lead to dopamine or is this where they start? Evidence from two epidemiologically informed developmental rodent models

The idea that there is some sort of abnormality in dopamine (DA) signalling is one of the more enduring hypotheses in schizophrenia research. Opinion leaders have published recent perspectives on the aetiology of this disorder with provocative titles such as 'Risk factors for schizophrenia--all roads lead to dopamine' or 'The dopamine hypothesis of schizophrenia--the final common pathway'. Perhaps, the other most enduring idea about schizophrenia is that it is a neurodevelopmental disorder. Those of us that model schizophrenia developmental risk-factor epidemiology in animals in an attempt to understand how this may translate to abnormal brain function have consistently shown that as adults these animals display behavioural, cognitive and pharmacological abnormalities consistent with aberrant DA signalling. The burning question remains how can in utero exposure to specific (environmental) insults induce persistent abnormalities in DA signalling in the adult? In this review, we summarize convergent evidence from two well-described developmental animal models, namely maternal immune activation and developmental vitamin D deficiency that begin to address this question. The adult offspring resulting from these two models consistently reveal locomotor abnormalities in response to DA-releasing or -blocking drugs. Additionally, as adults these animals have DA-related attentional and/or sensorimotor gating deficits. These findings are consistent with many other developmental animal models. However, the authors of this perspective have recently refocused their attention on very early aspects of DA ontogeny and describe reductions in genes that induce or specify dopaminergic phenotype in the embryonic brain and early changes in DA turnover suggesting that the origins of these behavioural abnormalities in adults may be traced to early alterations in DA ontogeny. Whether the convergent findings from these two models can be extended to other developmental animal models for this disease is at present unknown as such early brain alterations are rarely examined. Although it is premature to conclude that such mechanisms could be operating in other developmental animal models for schizophrenia, our convergent data have led us to propose that rather than all roads leading to DA, perhaps, this may be where they start.

Neuroanatomy and psychomimetic-induced locomotion in C57BL/6J and 129/X1SvJ mice exposed to developmental vitamin D deficiency

Evidence from epidemiology suggests that developmental vitamin D (DVD) deficiency is associated with an increased risk of schizophrenia. DVD deficiency in rats is associated with altered brain morphology and enhanced hyperlocomotion in response to MK-801 and amphetamine. The aim of this study was to determine if similar phenotypes were associated with DVD deficiency in two strains of mice (C57BL/6J, 129/X1SvJ). Brains from neonatal (P0) and adult (P70) mice were imaged using MRI and the volumes of the cerebrum, hippocampus, striatum, septum, cortex and ventricles measured, as well as the widths of white matter tracts. Locomotor sensitivity to 5mg/kg d-amphetamine, 0.5mg/kg MK-801 or saline was examined in a separate group of mice in an open field. DVD deficiency altered brain morphology in C57BL6/J mice, such that C57BL/6J female DVD-deficient neonatal mice had a smaller hippocampus compared to female controls. In addition, adult C57BL/6J male DVD-deficient mice had smaller lateral ventricles compared to controls, which may have been compressed by the enlarged striatum seen in these DVD-deficient mice. However, in contrast to the behavioural phenotypes found in DVD-deficient rats, there was no significant effect of maternal diet on amphetamine or MK-801-induced locomotion in either strain. These data indicate that not only species, but also strain of mouse, moderates the impact of DVD deficiency on neuroanatomical and behavioural phenotypes in rodent animal models.

Drugs in the brain--cellular imaging with receptor microscopic autoradiography

For cell and tissue localization of drugs, receptor microscopic autoradiography is reviewed, including its development history, multiple testing, extensive applications and significant discoveries. This sensitive high-resolution imaging method is based on the use of radiolabeled compounds (esp. tagged with (3)H or (125)I), preservation through freezing of in vivo localization of tissue constituents, cutting thin frozen sections, and close contact with the recording nuclear emulsion. After extensive testing of the utility of this method, the distribution of radiolabeled compounds has been identified and characterized for estradiol, progestagens, adrenal steroids, thyroid hormone, ecdysteroids, vitamin D, retinoic acid, metabolic indicators glucose and 2-deoxyglucose, as well as extracellular space indicators. Target cells and associated tissues have been characterized with special stains, fluorescing compounds, or combined autoradiography-immunocytochemistry with antibodies to dopamine-beta-hydroxylase, GABA, enkephalin, specific receptor proteins, or other cellular products. Blood-brain barrier and brain entries via capillary endothelium, ependyma, or circumventricular recess organs have been visualized for (3)H-dexamethasone, (210)Pb lead, and (3)H-1,25(OH)(2) vitamin D(3). With this histopharmacologic approach, cellular details and tissue integrative overviews can be assessed in the same preparation. As a result, information has been gained that would have been difficult or impossible otherwise. Maps of brain drug distribution have been developed and relevant target circuits have been recognized. Examples include the stria terminalis that links septal-amygdaloid-thalamic-hypothalamic structures and telencephalic limbic system components which extend as the periventricular autonomic-neuroendocrine ABC (Allocortex-Brainstem-Circuitry) system into the mid- and hindbrain. Discoveries with radiolabeled substances challenged existing paradigms, engendering new concepts and providing seminal incentives for further research toward understanding drug actions. Most notable are discoveries made during the 1980s with vitamin D in the brain together with over 50 target tissues that challenged the century-old doctrine of vitamin D's main role as 'the calcitropic hormone', when the new data made it apparent that the main biological function of this multifunctional sunshine hormone rather is maintenance of life and adapting vital functions to the solar environment. In the brain, vitamin D, in close relation to sex and adrenal steroids, participates in the regulation of the secretion of neuro-endocrines, such as, serotonin, dopamine, nerve growth factor, acetyl choline, with importance in prophylaxis and therapy of neuro-psychiatric disorders. Histochemical imaging with high cellular-subcellular resolution is necessary for obtaining detailed information, as this review indicates. New spectrometric methods, like MALDI-MSI, are unlikely to furnish the same information as receptor microautoradiography does, but can provide important correlative molecular information.

Vitamin D receptor and megalin gene polymorphisms and their associations with longitudinal cognitive change in US adults

BACKGROUND

Vitamin D receptor (VDR) and the megalin gene polymorphism's link with longitudinal cognitive change remains unclear.

OBJECTIVE

The associations of single nucleotide polymorphisms (SNPs) for VDR [rs11568820 (CdX-2:T/C), rs1544410 (BsmI:G/A), rs7975232 (ApaI:A/C), rs731236 (TaqI:G/A)], and Megalin (rs3755166:G/A; rs2075252:C/T; rs4668123:C/T) genes with longitudinal cognitive performance changes were examined.

DESIGN

Data from 702 non-Hispanic white participants in the Baltimore Longitudinal Study of Aging were used. Longitudinal annual rates of cognitive change (LARCCs) between age 50 y and the individual mean follow-up age were predicted with linear mixed models by using all cognitive score time points (prediction I) or time points before dementia onset (prediction II). Latent class, haplotype, and ordinary least squares (OLS) regression analyses were conducted.

RESULTS

Among key findings, in OLS models with SNP latent classes as predictors for LARCCs, Megalin(2) [rs3755166(-)/rs2075252(TT)/rs4668123(T-)] compared with Megalin(1) [rs3755166(-)/rs2075252(CC)/rs4668123(-)] was associated with greater decline among men for verbal memory (prediction II). Significant sex differences were also found for SNP haplotype (SNPHAP). In women, VDR(1) [BsmI(G-)/ApaI(C-)/TaqI(A-); baT] was linked to a greater decline in category fluency (prediction I: β = -0.031, P = 0.012). The Megalin(1) SNPHAP (GCC) was related to greater decline among women for verbal memory, immediate recall [California Verbal Learning Test (CVLT), List A; prediction II: β = -0.043, P = 0.006) but to slower decline among men for delayed recall (CVLT-DR: β > 0, P < 0.0125; both predictions). In women, the Megalin(2) SNPHAP (ACC) was associated with slower decline in category fluency (prediction II: β = +0.026, P = 0.005). Another finding was that Megalin SNP rs3755166:G/A was associated with greater decline in global cognition in both sexes combined and in verbal memory in men.

CONCLUSION

Sex-specific VDR and Megalin gene variations can modify age-related cognitive decline among US adults.

Progesterone and vitamin d hormone as a biologic treatment of traumatic brain injury in the aged

There is growing recognition that traumatic brain injury is a highly variable and complex systemic disorder that is refractory to therapies that target individual mechanisms. It is even more complex in elderly persons, in whom frailty, previous comorbidities, altered metabolism, and a long history of medication use are likely to complicate the secondary effects of brain trauma. Progesterone, one of the few neuroprotective agents that has shown promise for the treatment of acute brain injury, is now in national and international phase 3 multicenter trials. New findings show that vitamin D hormone (VDH) and VDH deficiency in the aging process (and across the developmental spectrum) may interact with progesterone and treatment for traumatic brain injury. In this article we review the use of progesterone and VDH as biologics-based therapies along with recent studies demonstrating that the combination of progesterone and VDH may promote better functional outcomes than either treatment independently.

The effects of vitamin D on brain development and adult brain function

A role for vitamin D in brain development and function has been gaining support over the last decade. Multiple lines of evidence suggest that this vitamin is actually a neuroactive steroid that acts on brain development, leading to alterations in brain neurochemistry and adult brain function. Early deficiencies have been linked with neuropsychiatric disorders, such as schizophrenia, and adult deficiencies have been associated with a host of adverse brain outcomes, including Parkinson's disease, Alzheimer's disease, depression and cognitive decline. This review summarises the current state of research on the actions of vitamin D in the brain and the consequences of deficiencies in this vitamin. Furthermore, we discuss specific implications of vitamin D status on the neurotransmitter, dopamine.

Vitamin D, the placenta and pregnancy

Impaired vitamin D status is common to many populations around the world. However, data suggest that this is a particular problem for specific groups such as pregnant women. This has raised important questions concerning the physiological and clinical impact of low vitamin D levels during pregnancy, with implications for classical skeletal functions of vitamin D, as well as its diverse non-classical actions. The current review will discuss this with specific emphasis on the classical calciotropic effects of vitamin D as well as the less well established immunological functions of vitamin D that may influence pregnancy outcome. The review also describes the pathways that are required for metabolism and function of vitamin D, and the various clinical complications that have been linked to impaired vitamin D status during pregnancy.

Role of vitamin D in multiple sclerosis: implications for disease management

SUMMARY This review discusses the evidence on the role of vitamin D in multiple sclerosis (MS) and whether vitamin D supplementation is effective for the management of MS. People with MS are at high risk of vitamin D deficiency, osteoporosis and fractures. Observational data suggest that higher vitamin D levels are associated with lower relapse risk and there is promising evidence on its effect on MRI measures, disability progression, mental health and fatigue. However, there is currently insufficient randomized controlled trial evidence to recommend vitamin D supplementation with the aim to improve those outcomes. There is sufficient evidence to justify assessing and correcting vitamin D and calcium levels to optimize bone health in people with MS at high absolute risk of fracture.

The promise of neuroprotective agents in Parkinson's disease

Parkinson’s disease (PD) is characterized by loss of dopamine neurons in the substantia nigra of the brain. Since there are limited treatment options for PD, neuroprotective agents are currently being tested as a means to slow disease progression. Agents targeting oxidative stress, mitochondrial dysfunction, and inflammation are prime candidates for neuroprotection. This review identifies Rasagiline, Minocycline, and creatine, as the most promising neuroprotective agents for PD, and they are all currently in phase III trials. Other agents possessing protective characteristics in delaying PD include stimulants, vitamins, supplements, and other drugs. Additionally, combination therapies also show benefits in slowing PD progression. The identification of neuroprotective agents for PD provides us with therapeutic opportunities for modifying the course of disease progression and, perhaps, reducing the risk of onset when preclinical biomarkers become available.

Vitamins and neural and cognitive developmental outcomes in children

The role of vitamin status in the development of the brain and the subsequent functioning of the brain was considered. There are data with a range of vitamins, from animal studies and human studies in developing countries, suggesting that a clinical deficiency during the critical period when the brain is developing causes permanent damage. To date there is, however, with the exception of cases of clinical deficiency such as those that might be associated with a vegan diet, little evidence that variations in the diet of those living in industrialised countries have a lasting developmental influence. Similarly, later in life clinical deficiencies of various vitamins disrupt cognition although there is to date limited evidence that variations in the intake of single vitamins in industrialised societies influence functioning. It may well be, however, unreasonable to expect that vitamins examined in isolation will be associated with differences in cognitive functioning. The output of the brain reflects millions of metabolic processes, each potentially susceptible to any of a range of vitamins. A diet poor in one respect is likely to be poor in other respects as well. As such, the preliminary reports in double-blind placebo-controlled trials that aspects of cognition and behaviour respond to supplementation with multi-micronutrients may indicate the way forward.

Vitamin D supplementation during pregnancy: double-blind, randomized clinical trial of safety and effectiveness

The need, safety, and effectiveness of vitamin D supplementation during pregnancy remain controversial. In this randomized, controlled trial, women with a singleton pregnancy at 12 to 16 weeks' gestation received 400, 2000, or 4000 IU of vitamin D(3) per day until delivery. The primary outcome was maternal/neonatal circulating 25-hydroxyvitamin D [25(OH)D] concentration at delivery, with secondary outcomes of a 25(OH)D concentration of 80 nmol/L or greater achieved and the 25(OH)D concentration required to achieve maximal 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] production. Of the 494 women enrolled, 350 women continued until delivery: Mean 25(OH)D concentrations by group at delivery and 1 month before delivery were significantly different (p < 0.0001), and the percent who achieved sufficiency was significantly different by group, greatest in 4000-IU group (p < 0.0001). The relative risk (RR) for achieving a concentration of 80 nmol/L or greater within 1 month of delivery was significantly different between the 2000- and the 400-IU groups (RR = 1.52, 95% CI 1.24-1.86), the 4000- and the 400-IU groups (RR = 1.60, 95% CI 1.32-1.95) but not between the 4000- and. 2000-IU groups (RR = 1.06, 95% CI 0.93-1.19). Circulating 25(OH)D had a direct influence on circulating 1,25(OH)(2)D(3) concentrations throughout pregnancy (p < 0.0001), with maximal production of 1,25(OH)(2)D(3) in all strata in the 4000-IU group. There were no differences between groups on any safety measure. Not a single adverse event was attributed to vitamin D supplementation or circulating 25(OH)D levels. It is concluded that vitamin D supplementation of 4000 IU/d for pregnant women is safe and most effective in achieving sufficiency in all women and their neonates regardless of race, whereas the current estimated average requirement is comparatively ineffective at achieving adequate circulating 25(OH)D concentrations, especially in African Americans.

Vitamin D in the healthy and inflamed central nervous system: access and function

High exposure to vitamin D may protect against development and progression of multiple sclerosis (MS), possibly through the immunomodulatory properties of its biologically active metabolite 1,25-dihydroxyvitamin D. So far, most studies on the possible mechanisms for vitamin D involvement in MS have focused on immune modulation outside the central nervous system (CNS). However, vitamin D may also interfere with the pathophysiology of MS within the CNS. In this review, the potential presence and functions of vitamin D in the inflamed and healthy CNS are explored. We discuss that vitamin D, vitamin D binding protein (DBP), the vitamin D receptor (VDR) and enzymes needed for metabolism (CYP27B1) are present in the CNS. Both VDR and CYP27B1 are expressed on a variety of cells, including neurons, glial cells, and invading lymphocytes. Additionally, vitamin D has been postulated to play a modulating role in several key-processes in MS pathophysiology, including inflammation, demyelination, axonal damage, and remyelination. We conclude that a local role of vitamin D in the inflamed CNS is likely and potentially relevant to MS. Future studies should further characterize the impact of vitamin D on the local disease process of MS in the CNS.

Vitamin D in fetal brain development

In this review we will provide a concise summary of the evidence implicating a role for vitamin D in the developing brain. Vitamin D is known to affect a diverse array of cellular functions. Over the past 10 years data has emerged implicating numerous ways in which this vitamin could also affect the developing brain including its effects on cell differentiation, neurotrophic factor expression, cytokine regulation, neurotransmitter synthesis, intracellular calcium signaling, anti-oxidant activity, and the expression of genes/proteins involved in neuronal differentiation, structure and metabolism. Dysfunction in any of these processes could adversely affect development. Although there are many ways to study the effects of vitamin D on the developing CNS in vivo, we will concentrate on one experimental model that has examined the impact of the dietary absence of vitamin D in utero. Finally, we discuss the epidemiological data that suggests that vitamin D deficiency either in utero or in early life may have adverse neuropsychiatric implications.

Vitamin D insufficiency is associated with impaired vascular endothelial and smooth muscle function and hypertension in young rats

Increasing evidence links vitamin D deficiency and cardiovascular dysfunction in human adults. There is a worldwide increase in the prevalence of vitamin D deficiency in women of reproductive age, particularly dark-skinned and/or veiled women and their infants. We used a rat model to determine the functional impact of vitamin D deficiency during intra uterine and early life on resistance artery reactivity and blood pressure in the offspring as young adults. Rat dams were maintained on vitamin D deficient or replete chow before and during pregnancy and lactation. The offspring were maintained on the same chow until studied at 7-8 weeks of age. Conscious blood pressure was measured. Endothelial and smooth muscle function were tested in mesenteric arteries on a pressure myograph. Vitamin D deficient male and female offspring had a 10-fold lower serum 25-hydroxyvitamin D (P < 0.0001) and markedly elevated blood pressures (11-20 mmHg, P < 0.001) and heart rates (21-40 beats min(-1), P < 0.02) than control fed offspring. Serum calcium was unchanged. Mesenteric artery myogenic tone was doubled in vitamin D deficiency. Endothelium-derived nitric oxide-evoked dilation was halved in arteries from vitamin D deficient males and dioestrous females. Dilation attributed to endothelium-derived hyperpolarizing factor was all but abolished in vitamin D deficient oestrous females. Nitroprusside-evoked dilation was unaltered in arteries from males, but was markedly reduced in vessels of vitamin D deplete females. In conclusion, early life vitamin D deficiency is associated with endothelial vasodilator dysfunction, and this is likely to contribute to the accompanying elevation in blood pressure and an increased cardiovascular disease risk.

Vitamin D and the brain

Vitamin D is a member of the superfamily of nuclear steroid transcription regulators and as such, exerts transcriptional control over a large number of genes. Several other steroids, such as thyroid hormones, vitamin A, androgens and the glucocorticoids, are known as 'neurosteroids' and their role in brain development and function is well defined. It has only been in the last decade or so that vitamin D has been thought to function as a neurosteroid. In this review we have collated a diverse array of data describing the presence of vitamin D metabolites and the receptor in the brain, the evidence that vitamin D may be an important modulator of brain development, and the potential role of vitamin D in neurological and neuropsychiatric disorders.

Association of hypomelanotic skin disorders with autism: links to possible etiologic role of vitamin-D levels in autism?

Vitamin D is crucial for several key physiological processes, including brain development, DNA repair, and regulation of many genes. Much evidence indicates prenatal and early postnatal vitamin-D deficiency increases autism risk, probably through multiple effects, including impaired brain development and increased de novo mutations. High autism rates in several genetically based hypomelanotic skin disorders are puzzling, because ultraviolet-B radiation (UVB) in sunlight acting on skin is a key source of vitamin-D, and lighter skin protects against vitamin-D deficiency, especially at high latitudes. We consider two hypotheses to help explain autism's co-morbidity with hypomelanosis. 1) Because genetic and epigenetic variants that produce hypomelanosis help protect against vitamin-D deficiency, they increase reproductive fitness of individuals who also have other autism risk factors. 2) Hypomelanotic children have increased autism risk because photosensitivity and skin-cancer concerns lead families to excessively reduce children's sun exposure. Hypothesis testing could involve studies comparing genomes, epigenetic markers, skin pigmentation, and vitamin-D levels in autistic individuals with and without hypomelanosis, their relatives and controls. Conducting such studies in samples from regions that differ widely in UVB availability would provide particularly valuable data. Support for either hypothesis would elucidate vitamin-D's role in autism and suggest vitamin-D enhancement may aid treatment and prevention of autism.

VITAMIN D AND HUMAN PREGNANCY

At the end of 2007, Time magazine listed the “benefits of vitamin D” as one of its top 10 medical breakthroughs for that year. Since then there has been a remarkable upsurge of interest in vitamin D, with new research advances seemingly published on a weekly basis. In particular, there has been increasing awareness of the variability of vitamin D status in populations across the globe and, significantly, a growing debate about the need for revised parameters for vitamin D supplementation. Although sub-optimal vitamin D is likely to be a widespread problem for 21stcentury societies, it is also clear that some groups are at much greater risk of low vitamin D status. Prominent amongst these are pregnant women and the aim of the following review article will be to discuss this problem in further detail with specific emphasis on its potential physiological and clinical impact.

Prevention and schizophrenia--the role of dietary factors

Adequate prenatal nutrition is essential for optimal brain development. There is a growing body of evidence from epidemiology linking exposure to nutritional deprivation and increased risk of schizophrenia. Based on studies from the Netherlands and China, those exposed to macronutrient deficiencies during famine have an increased risk of schizophrenia. With respect to micronutrients, we focus on 3 candidates where there is biological plausibility for a role in this disorder and at least 1 study of an association with schizophrenia. These nutrients include vitamin D, folic acid, and iron. While the current evidence is incomplete, we discuss the potential implications of these findings for the prevention of schizophrenia. We argue that schizophrenia can draw inspiration from public health interventions related to prenatal nutrition and other outcomes and speculate on relevant factors that bear on the nature, risks, impact, and logistics of various nutritional strategies that may be employed to prevent this disorder.

Relationship between vitamin D during perinatal development and health

Vitamin D deficiency is a highly prevalent condition that is present in 40% to 80% of pregnant women. There is emerging evidence that vitamin D deficiency may be a risk modifying factor for many chronic diseases, including osteomalacia, rickets, multiple sclerosis, schizophrenia, heart disease, type 1 diabetes, and cancer. Heightened susceptibility to these diseases may originate in early life during the development of tissue structure and function. It is suspected that biologic mechanisms can "memorize" the metabolic effects of early nutritional environment through fetal and neonatal imprinting. Inadequate vitamin D nutrition during perinatal life may establish a poor foundation that may produce long-term threats to human health. This review summarizes the risks of vitamin D deficiency for human health and provides the current vitamin D recommendations for mothers and their newborns.