Abstract Objective: To estimate the prevalence of vitamin D deficiency and severe deficiency in children and adolescents, in a large Brazilian sample. Methodology: Results of 413,988 25(OH)D measurements in children and adolescents aged 0 to 18 years collected between 01/2014 and 10/2018 were obtained from the database of a Clinical Laboratory. In this population, 25 hydroxyvitamin D concentrations below 20 ng/mL are considered deficient, and below 12 ng/mL as severe deficiency. All measurements were performed by immunoassay and the results were distributed by gender, age group, seasonality, and latitude. Results: The mean of 25(OH)D levels was 29.2 ng/mL with a standard deviation of 9.2 ng/mL. Of the total samples, 0.8% had a concentration < 12 ng/mL, and 12.5% of the samples had a concentration < 20 ng/mL, with a higher prevalence in females. Children under 2 years of age had the lowest prevalence. The effects of latitude and seasonality were quite evident. In samples of female adolescents from the southern region in winter, 36% of vitamin D deficiency and 5% of severe deficiency were found. Conclusion: In this large number of measurements of 25(OH)D in children and adolescents, 12.5% had a deficiency and 0.8% had severe deficiency. A greater deficiency was observed among adolescents, especially females, which raises questions about the need for supplementation during this period of life. Objective sample Methodology 413988 413 988 413,98 25OHD OHD OH 1 012014 01 2014 01/201 102018 10 2018 10/201 Laboratory population ngmL ng mL deficient gender group 292 29 29. 92 9 9. 08 8 0.8 125 5 12.5 females evident winter 36 found Conclusion life 41398 41 98 413,9 01201 201 01/20 10201 10/20 0. 12. 3 4139 4 413, 0120 01/2 1020 10/2 012 01/ 102 10/

ABSTRACT Background: Lactose tolerant test (LTT) is the most broadly used diagnostic test for lactose intolerance in Brazil, is an indirect, minimally invasive and a low-cost test that is widely available in primary care and useful in clinical practice. The C/T-13910 polymorphism in lactase persistence has been well characterized in Caucasian populations, but there are no studies evaluating the concordance between C/T-13910 polymorphism genotyping results and LTT results in Brazil, where the population is highly mixed. Objective: We aimed to evaluate agreement between presence of C/T-13910 polymorphism genotyping and malabsorption in LTT results. Methods: This is a retrospective analysis of a Brazilian population whose data were collected from a single laboratory database present in several Brazilian states. Results of individuals who underwent both genetic testing for lactose intolerance (C/T-13910 polymorphism genotyping) and an LTT from April 2016 until February 2019 were analysed to evaluate agreement between tests. Groups were classified according to age (<10-year-old (yo), 10-17 yo, ≥18 yo groups) and state of residence (São Paulo or Rio Grande do Sul). Results: Among the 404 patients evaluated, there was agreement between the genotyping and LTT results in 325 (80.4%) patients and discordance in 79 (19.6%) patients (k=0.42 -moderate agreement). Regarding the genotype, 47 patients with genotype C/C (lactase nonpersistence) had normal LTT results, and 32 with genotype C/T or T/T (indicating lactase persistence) had abnormal LTT results. Neither age nor state of residence (Rio Grande do Sul or São Paulo) affected the agreement between test results. Conclusion: Considering the moderate agreement between C/T-13910 polymorphism genotyping and LTT results (κ=0.42) in the Brazilian population, we hypothesize that an analysis of other polymorphisms could be a strategy to improve the agreement between genotyping and established tests and suggest that additional studies should focus on exploring this approach. Background (LTT Brazil indirect lowcost low cost practice C/T13910 CT13910 CT 13910 C T C/T-1391 populations mixed Objective Methods states (C/T-1391 201 <10yearold 10yearold yearold <10 year old 10 , (yo) 1017 17 10-1 18 ≥1 groups Sul. . Sul) 40 evaluated 80.4% 804 80 4 (80.4% 7 19.6% 196 19 6 (19.6% k=0.42 k042 k 0 42 (k=0.4 agreement. agreement) CC nonpersistence 3 TT indicating Conclusion κ=0.42 κ042 κ (κ=0.42 approach T13910 C/T1391 CT1391 1391 C/T-139 (C/T-139 20 <1 1 (yo 101 10- ≥ 80.4 8 (80.4 19.6 (19.6 k=0.4 k04 (k=0. κ=0.4 κ04 (κ=0.4 T1391 C/T139 CT139 139 C/T-13 (C/T-13 2 < 80. (80. 19. (19. k=0. k0 (k=0 κ=0. κ0 (κ=0. T139 C/T13 CT13 13 C/T-1 (C/T-1 (80 (19 k=0 (k= κ=0 (κ=0 T13 C/T1 CT1 C/T- (C/T- (8 (1 k= (k κ= (κ= T1 (C/T ( (κ

RESUMO Contexto: O teste de tolerancia à lactose (TTL) é ampliamente utilizado por ser minimamente invasivo e de baixo custo, disponível na atenção primária e muito útil na prática clínica. Está bem estabelecido o polimorfismo C/T-13910 na persistência da lactase em populações caucasianas, mas não há estudos avaliando a concordância entre os resultados da genotipagem do polimorfismo C/T-13910 e do TTL no Brasil, onde a população é altamente miscigenada. Objetivo: Avaliar a concordância entre a presença do polimorfismo C/T-13910 e a má absorção nos resultados do TTL. Métodos: Análise retrospectiva de dados coletados de um laboratorio presente em vários estados brasileiros. Os resultados dos pacientes que realizaram um teste genético para intolerância à lactose (genotipagem do polimorfismo C/T-13910) e um TTL de abril de 2016 a fevereiro de 2019 foram analisados para avaliar a concordância entre os testes. Os grupos foram classificados de acordo com a idade (<10 anos; 10-17 anos, ≥18 anos) e estado de residência (São Paulo ou Rio Grande do Sul). Resultados: Entre os 404 pacientes avaliados, houve concordância entre os resultados de genotipagem e TTL em 325 (80,4%) pacientes e discordância em 79 (19,6%) pacientes (K=0,42 - concordância moderada). Em relação ao genótipo, 47 pacientes com genótipo C/C (não persistência de lactase) apresentaram TTL normal e 32 com genótipo C/T ou T/T (indicando persistência da lactase) apresentaram TTL anormal. A idade e o estado de residência (Rio Grande do Sul ou São Paulo) não afetaram a concordância entre os resultados dos exames. Conclusão: Considerando a concordância moderada entre a genotipagem do polimorfismo C/T-13910 e os resultados de TTL (κ=0,42) na população brasileira, sugerimos que a análise de outros polimorfismos poderia ser uma estratégia para melhorar a concordância entre os testes. Contexto (TTL custo clínica C/T13910 CT13910 CT 13910 C T C/T-1391 caucasianas Brasil miscigenada Objetivo Métodos brasileiros 201 testes <10 10 (<1 anos 1017 17 10-1 18 ≥1 Sul. . Sul) Resultados 40 avaliados 80,4% 804 80 4 (80,4% 7 19,6% 196 19 6 (19,6% K=0,42 K042 K 0 42 (K=0,4 moderada. moderada) CC 3 TT indicando anormal exames Conclusão κ=0,42 κ042 κ (κ=0,42 brasileira T13910 C/T1391 CT1391 1391 C/T-139 20 <1 1 (< 101 10- ≥ 80,4 8 (80,4 19,6 (19,6 K=0,4 K04 (K=0, κ=0,4 κ04 (κ=0,4 T1391 C/T139 CT139 139 C/T-13 2 < ( 80, (80, 19, (19, K=0, K0 (K=0 κ=0, κ0 (κ=0, T139 C/T13 CT13 13 C/T-1 (80 (19 K=0 (K= κ=0 (κ=0 T13 C/T1 CT1 C/T- (8 (1 K= (K κ= (κ= T1 (κ