Diabetes mellitus, a chronic illness, is characterized by pancreatic and insulin dysfunction. Under the influence of

sunlight, vitamin D (V-D) is produced in the skin in a non-enzymatic manner. Furthermore, V-D can be obtained

via fish or plant sources. Different studies conducted in Saudi Arabia have been shown high occurrence of V-D

inadequacy. Obesity and type 2 diabetes are both linked to V-D insufficiency. Still, this relationship's causality is

unknown. A growing body of research suggests that changes in V-D and calcium homeostasis may play a role in

the development of type 2 diabetes. This study aimed to ascertain the occurrence of V-D deficiency in the

Northern borders (NB) of Saudi Arabia and to verify the connection between V-D deficiency and other features of

study subjects. During the period from July 2018 to February 2019, a cross-sectional study was carried out. A

random sampling method was employed to choose the required numbers of subjects who have type 1 or type II

diabetes and are registered in NB region health centers and hospitals. The sample size was calculated using the

one-sample proportion formula and the results of similar studies. These results revealed the situation in the NB

Region of Saudi Arabia among diabetic patients and highlight the importance of addressing the issue. The

correlation between V-D and hypertension was also found in the study, requiring further investigation and

explanation.

Keywords: Diabetes mellitus; vitamin D deficiency; hypertension; Saudi Arabia