Correlation Between Nutritional Status and Serum Vitamin D Level in Children Sihombing L B a* , Sembiring T, Sugih Arto K, Pratita W a dr_leosihombing@yahoo.com Departemen Ilmu Kesehatan Anak Fakultas Kedokteran Universitas Sumatera Utara, Medan-Indonesia Abstract Introduction : Vitamin D has various essential roles in the physiological functions of the body. The incidence of vitamin D insufficiency in Indonesia is 49.3%. Malnourished children tend low serum vitamin D levels due to impaired synthesis. Children with poor nutrition have less subcutaneous tissue and are more often at home so they are rarely exposed to sunlight.. Aim : To assess the correlation between nutritional status and serum vitamin D level in children. Methods: This cross-sectional study was conducted in outpatient and inpatient pediatric services at H. Adam Malik Hospital from March to October 2020. Sample characteristics were obtained through interviews with parents and the results of anthropometric measurements and vitamin D levels of the study sample. Results: Of the 60 children consisting of 30 children with well-nourished and 30 malnourished, the average serum vitamin D level was 19.38 ng/mL, with normal 35%, insufficiency 43.3%, and deficiency 21.7%. The Chi-Square test showed a significant relationship between nutritional status and vitamin D levels (p=0.02) and a prevalence ratio of 1.6 with 95% CI. Conclusion: Positive association between nutritional status and serum vitamin D level in children was found in this study. Key Words: vitamin D; well-nourished; malnourished 1. Introduction Nutritional problems in children are caused by inadequate or excessive food intake to meet the body's needs. 1 Assessment of nutritional status aims to determine the prevalence of nutritional status at a certain time or to determine the development of the prevalence of nutritional status in the population from time to time. 2 Vitamin D is a pro-hormone that has various substantial roles in the physiological functions of the body. 3 Vitamin D status in the body is determined based on the level of 25(OH)D, which has a fairly long half- life of 2-3 weeks. 4 In a study conducted in four countries, Indonesia was ranked fourth, with an average vitamin D serum level of only 52.7 nmol/l (16.5ng/mL). 5 Research in Pakistan has shown that giving high doses of vitamin D to severely malnourished children responds to weight gain and muscle mass. 6,7 Children with poor nutrition have little subcutaneous tissue so that the synthesis of vitamin D in the skin is disrupted, where vitamin D will not be converted into active metabolites. 8 Vitamin D synthesis disorders are also found in malnourished children because they usually suffer from chronic diseases that cause children to be inactive and more often at home, so they are rarely exposed to sunlight. This causes a tendency to decrease serum vitamin D levels due to impaired synthesis. 9 Research on the relationship between serum vitamin D levels in malnourished children in Indonesia has not been conducted. In a state of malnutrition, there is a decrease in the concentration of vitamin D receptors. The sensitivity of vitamin D binding protein (DBP) to protein and energy intake could form a new mechanism that could explain the relationship between malnutrition and bone development and metabolic diseases. 10,11 Vitamin D receptors transport 95%-99% of 25(OH)D in the body. The main component of DBP is a protein (α globulin). Albumin and lipoproteins carry a small proportion of vitamin D metabolites, although they are more widely circulated in the blood circulation than DBP. Children who suffer from malnutrition will experience a decrease in the concentration of DBP in the blood circulation. 11 However, DBP levels were not affected by insufficient calcium intake. There was no effect of food intake on DBP's affinity for its main ligand, namely 25 (OH)D. 10,11 Imawari reported that protein concentration decreased in malnourished children so that vitamin D would decrease due to a decrease in vitamin D binding protein. However, the results showed that there was no change in vitamin D levels even though there was a decrease in the amount of serum albumin. Because the research subjects are children who live in poverty are more often exposed to the sun even though they get a small intake 146 www.ijrp.org IJRP 2021, 83(1), 146-151; doi:.10.47119/IJRP100831820212203