The effect of skin thickness on vitamin D levels! Where do you measure from?

Objective: Vitamin D is a steroid hormone, about 80-90% of which is produced by the skin. On the other hand, its deficiency is very common and its treatment is of great importance due to its multisystem effects. In addition to factors affecting vitamin D levels such as skin color, sunscreen used, geographical location, and obesity, there are also studies related to the effect of skin thickness. It was aimed to determine the effect of skin thickness and subcutaneous adipose tissue measurements on vitamin D results in the areas where there is the most contact with the sunlight in our body, in the study. Methods: A total of 116 (71 female, 45 male) volunteers were included in the study. The results of vitamin D in the last month, demographic data, height, and weight were recorded. Skin thickness and subcutaneous adipose tissue measurements performed by ultrasound were recorded from the forehead, cheek, hand dorsum, umbilicus, and trochanter major regions. Results: The exposure time to the sun (r=0.637, p<0.001), the statistically significant difference between the results of the trochanter major subcutaneous adipose tissue (r=0.347, p<0.001) and subcutaneous adipose