Vitamin D and Immunity in Infants and Children.

The last couple of decades have seen an explosion in our interest and understanding of the role of vitamin D in the regulation of immunity. At the molecular level, the hormonal form of vitamin D signals through the nuclear vitamin D receptor (VDR), a ligand-regulated transcription factor. The VDR and vitamin D metabolic enzymes are expressed throughout the innate and adaptive arms of the immune system. The advent of genome-wide approaches to gene expression profiling have led to the identification of numerous VDR-regulated genes implicated in the regulation of innate and adaptive immunity. The molecular data infer that vitamin D signaling should boost innate immunity against pathogens of bacterial or viral origin. Vitamin D signaling also suppresses inflammatory immune responses that underlie autoimmunity and regulate allergic responses. These findings have been bolstered by clinical studies linking vitamin D deficiency to increased rates of infections, autoimmunity, and allergies. Our goals here are to provide an overview of the molecular basis for immune system regulation and to survey the clinical data from pediatric populations, using randomized placebo-controlled trials and meta-analyses where possible, linking vitamin D deficiency to increased rates of infections, autoimmune conditions, and allergies, and addressing the impact of supplementation on these conditions.

Global challenges in acute diarrhea.

PURPOSE OF REVIEW: Childhood diarrhea is the most common cause of morbidity and mortality, especially in the low and middle-income countries. The burden of child mortality because of diarrhea has declined, but still a lot is desired not only to reduce diarrhea-specific mortality but reduce the overall incidence, and hence the morbidity associated with childhood diarrhea. RECENT FINDINGS: A recent Lancet series on diarrhea suggests that amplification of the current interventions can eliminate virtually all preventable diarrhea deaths. A refocused attention and strategy and collective effort from the multilateral entities to promote water sanitation and hygiene, rotavirus vaccination, nutrition, and improved case management can bridge gaps and tackle the existing undue burden of deaths because of diarrhea. SUMMARY: Investment toward preventing and controlling childhood diarrhea should be a priority, especially when the existing solution is plausible for implementation at scale and in underprivileged settings.

Global burden of childhood diarrhea and interventions.

PURPOSE OF REVIEW: Diarrhea is a leading cause of morbidity and mortality among children under 5 years in low-income and middle-income countries. Over the past 2 decades under-five mortality has decreased substantially, but reductions have been uneven and unsatisfactory in resource-poor regions. RECENT FINDINGS: There are known interventions which can prevent diarrhea or manage children who suffer from it. Interventions with proven effectiveness at the prevention level include water, sanitation, and hygiene interventions, breastfeeding, complementary feeding, vitamin A and zinc supplementation, and vaccines for diarrhea (rotavirus and cholera). Oral rehydration solution, zinc treatment, continued feeding, and antibiotic treatment for certain strains of diarrhea (cholera, Shigella, and cryptosporidiosis) are effective strategies for treatment of diarrhea. The recent Lancet series using the 'Lives Saved' tool suggested that if these identified interventions were scaled up to a global coverage to at least 80%, and immunizations to at least 90%; almost all deaths due to diarrhea could be averted. SUMMARY: The current childhood mortality burden highlights the need of a focused global diarrhea action plan. The findings suggest that with proper packaging of interventions and delivery platforms, the burden of childhood diarrhea can be reduced to a greater extent. All that is required is greater attention and steps toward right direction.

The Immunomodulating Effect of a Diet Consisting of Green Vegetables, Beef, Whole Milk and Full-Fat Butter for Children with Non-Specific Elevated IgE.

BACKGROUND: Non-specific elevated IgE and allergies are common in children, and their prevalence is increasing. Dietary changes could be an explanation for this increase. Zinc, iron, vitamins A, C and E, and polyunsaturated fatty acids all play possible roles in the etiology and possible treatment of allergies due to their numerous immunomodulating properties. OBJECTIVES: To investigate the immunomodulating effect of recommending a nutrient-rich diet consisting of green vegetables, beef, whole milk and full-fat butter. METHODS: We conducted a case-controlled, non-randomized, retrospective study. Children between the ages of 1 and 18 years with non-specific elevated IgE were included. Baseline and follow-up measurements of serum total IgE and clinical outcomes were retrospectively collected and compared for 49 children who received the dietary advice (to eat green vegetables, beef, whole milk and full-fat butter) and 56 children who did not. RESULTS: The initial analysis showed a significantly greater decrease in IgE in the intervention group compared to the control group; a 9.2 kU/l versus a 0.1 kU/l decrease, respectively (P = 0.02). When supplement (vitamin D) use was taken into account, however, no significant difference was produced by the dietary effect alone (unstandardized coefficient = 71.3 kU/l, P = 0.16). 53.2 % of participants in the intervention group reported considerable improvement in symptoms versus 28.6 % in the control group (P < 0.001). CONCLUSION: Overall, the effects of nutrients and vitamins on the decrease in IgE are promising. The separate contributions of dietary advice and/or supplements need to be investigated in the future.