Abstract
Background: Over the last decade, there was significant interest in the role of vitamin D in general health, which led to a dramatic increase in vitamin D testing and supplementation.
Objective: To evaluate the status of vitamin D among Saudi female students at the Health Sciences Colleges and compare the levels of 25-OHD between two generations.
Materials and methods: A cross sectional study was carried out at Health Sciences Colleges, Taibah University, Medina, Saudi Arabia. Serum 25-OHD levels were measured in 270 students during the academic years of 2011 and 2018; 135 students from each year, using electrochemiluminescence method. Vitamin D status was classified according to the recent consensus agreement in the optimal level of 25-OHD concentrations (>= 75 nmol/L is the optimal level and < 50 nmol/L is a deficiency) [referred to as the high cutoff value] versus the Institute of Medicine (IOM) criteria (>= 50 nmol/L is the optimal level, and < 25 nmol/L is a deficiency) [referred to as the low cutoff value]. Parathyroid hormone (PTH) levels were measured for the 2011 group only.
Results: The mean age of the subjects was 22.0 +/- 2.134 and the mean level of 25-OHD was 21.5 +/- 8.375 nmol/L with no differences between the two groups. The prevalence of vitamin D deficiency was 99.3% when the high cutoff value was applied versus 69.1% when the low cutoff value was applied, with no significant differences between the two groups. The mean PTH level was 3.81 +/- 2.1 pmol/L, and only 5.1% of the studied group had PTH levels above the normal range.
Conclusion: Despite the recent trends in vitamin D testing and supplementation, vitamin D deficiency remains highly prevalent among the Saudi population, affecting even healthy active young students from the Health Sciences Colleges with no differences between generations. This overestimation is most likely caused by applying the current recommended cutoff levels for defining the adequacy of 25-OHD. Future studies are needed to define the optimal level of 25-OHD concentrations in the Saudi/Gulf population.