Vitamin D and Omega-3 (Fatty Acid) Supplementation in Pregnancy for the Primary Prevention of Food Allergy in Children-Literature Review

Abstract

During the last decades the prevalence of food allergy (FA), an adverse immune response to a specific food antigen, has risen, with negative effects on the quality of life (QoL) of many children and their families. The pathogenesis of FA is complex, involving both genetic and environmental factors. SPINK5, STAT6, HLA and FOXP3 are some of the genes that are reported to be implicated in FA development. Regarding environmental factors, particular interest has been focused on modification of the dietary habits of pregnant women for the primary prevention of FA. Specifically, Vitamin D and omega-3 (Ω-3) fatty acid supplementation during pregnancy may influence the development of FA in the offspring. Vitamin D is a hormone with various actions, including mediation of the immune system, reducing the production of inflammatory cytokines and promoting tolerance. Vitamin D deficiency in pregnancy suppresses T-regulatory cells in the fetus, and Vitamin D supplementation might protect against FA development. Dietary Ω-3 fatty acids are found mainly in fish and vegetable oils. They are beneficial for human health, playing a role in the immune system as anti-inflammatory agents, and providing cell membrane stabilization with inhibition of antigen presentation. It is documented that maternal supplementation with Ω-3 during pregnancy may protect from allergic sensitization in the children. The aim of this literature review was to explore the potential preventive role of maternal supplementation during pregnancy with Vitamin D and Ω-3 in the development of FA in the offspring. With the prevalence of FA rising, all the possible protective mechanisms and measures for FA prevention need to be explored, starting with those that can be modified.

Dietary strategies for early immune modulation in primary food allergy prevention

“…This finding concurred with the observation that the prevalence of food allergy and eczema was higher in regions with less sun exposure and lower skin-derived vitamin D levels 40. By contrast, excess vitamin D levels may have undesirable immune-modulating effects and increase the risk of allergic sensitisation via the inhibition of dendritic cell maturation, suggesting a U-shaped effect curve 32 41. The WHO recommends a daily vitamin D intake for women of 600 IU/day.…”

“…Omega-3 fatty acids (FAs) are a family of unsaturated fatty acids with anti-inflammatory properties 32. Dietary sources of omega-3 FAs include oily fish (eg, mackerel, tuna, salmon, sardines), fish oil, seeds (eg, linseed, flaxseed, chia seed) and plant oils (eg, walnut, canola).…”

“…Three omega-3 fatty long-chain polyunsaturated fatty acids (LCPUFA) have known health benefits, that is, eicosapentaenoic acid (EPA), docosapentaenoic acid and docosahexaenoic acid (DHA), including improved phospholipid membrane integrity, as well as cerebral and retinal development (table 2). 32 LCPUFAs are able to regulate macrophage activation and Treg which both promote tolerance development 32. One of the mechanisms involved in the modulation of infantile T cell responses occurs via epigenetic modification of histone acetylation in the PKCζ promotor gene region 33…”

“…In its active form, vitamin D 3 (calcitriol) regulates calcium and phosphate metabolism, and has effects on keratinocytes, endothelial cells, osteoblasts and lymphocytes 32. The majority of vitamin D 3 is generated in the skin after UVB light exposure which induces the conversion of 7-dehydrocalciferol to provitamin D 3 .…”

“…The WHO recommends a daily vitamin D intake for women of 600 IU/day. Additional supplementation during pregnancy for the purposes of food allergy prevention is currently not recommended 11 32…”