Vitamin D status and its relation to insulin resistance in a Mexican pediatric population.

Background Obesity in children and adolescents has increased alarmingly, placing them at a higher risk for impaired glucose tolerance and type 2 diabetes. The prevalence of vitamin D deficiency has increased as well. Vitamin D is critical for glucose homeostasis and insulin secretion. Studies on adults have reported an inverse association between vitamin D levels and insulin resistance (IR), but the results in children are inconsistent. The aim of our study was to determine the association between IR and serum vitamin D levels in obese Mexican children and adolescents. Methods A cross-sectional study was performed on 227 children and adolescents between 6 and 19 years of age. Obesity was diagnosed through body mass index (BMI) for age, according to the World Health Organization (WHO) criteria (2007). 25-Hydroxyvitamin D (25[OH]D) was measured using an immunoassay technique and the homeostatic model assessment of insulin resistance (HOMA-IR) was calculated using the Matthews equation. Student's t-test was carried out. Results The mean serum 25(OH)D level was 35.80 ng/mL, and 55.1% of the subjects had levels classified as sufficient, 33.5% as insufficient, and 11.5% as deficient. The mean level of HOMA-IR was 3.16, and 70% of the subjects were diagnosed with IR. Fasting insulin levels and HOMA-IR were significantly different in adolescents with hypovitaminosis, compared with adolescents in the vitamin D sufficiency group (p = 0.01 and p = 0.03, respectively). Conclusions The insulin levels and HOMA-IR were higher in adolescents with hypovitaminosis. The girls presented higher levels of insulin and HOMA-IR than the boys.

Chemical and Functional Properties of Chia Seed (Salvia hispanica L.) Gum.

Chia (Salvia hispanica L.) constitutes a potential alternative raw material and ingredient in food industry applications due to its dietary fiber content. Gum can be extracted from its dietary fiber fractions for use as an additive to control viscosity, stability, texture, and consistency in food systems. The gum extracted from chia seeds was characterized to determine their quality and potential as functional food additives. The extracted chia gum contained 26.2% fat and a portion was submitted to fat extraction, producing two fractions: gum with fat (FCG) and gum partly defatted (PDCG). Proximal composition and physicochemical characterization showed these fractions to be different (P < 0.05). The PDCG had higher protein, ash, and carbohydrates content than the FCG, in addition to higher water-holding (110.5 g water/g fiber) and water-binding capacities (0.84 g water/g fiber). The FCG had greater oil-holding capacity (25.7 g oil/g fiber) and water absorption capacity (44 g water/g fiber). In dispersion trials, the gums exhibited a non-Newtonian fluid behavior, specifically shear thinning or pseudoplastic type. PDCG had more viscosity than FCG. Chia seed is an excellent natural source of gum with good physicochemical and functional qualities, and is very promising for use in food industry.