رسائل ماجيستير
English
2022
Establishment of Vitamin D Reference Values in the Palestinian Society and Investigation of Cultural, Behavioral, and Socioeconomic Effects
أحمد يونس عمرو, محمد إبراهيم عيسى المحاريق
كلية الطب البشري-جامعة القدس · فلسطين
This thesis documents several key contributions made to the vitamin D field. Vitamin D is recognized as the sunshine vitamin under regular sun exposure conditions. Unsurprisingly, vitamin D dietary intake is considered of minor importance in science; however, sun exposure reveals about 90% of vitamin D production.
In the last decade, vitamin D testing and the use of vitamin D supplements have increased significantly, with neither clear nor agreed-upon recommendations on blood level reference values of vitamin D in healthy individuals.
The recommended sufficient level of serum vitamin D is ≥30 ng/mL (≥75 nmol/L). In contrast, vitamin D deficiency is defined as 25(OH)D levels ≤20 ng/mL (≤50 nmol/L), and the serum level between 20 and 30 ng/mL (50–75 nmol/L) indicates insufficiency.
The main objective of this study is to establish a population-based reference range of vitamin D in Palestinian society and to investigate its associated cultural, socioeconomic, and human behavioral factors.
We adopted a cross-sectional study that was conducted on 300 healthy Palestinian individuals from different cities and villages in the West Bank. Those individuals did not report a history of kidney, liver, or malabsorption disorders. The sample consisted of 123 males and 177 females aged between 19 and 65 years old.
We used a structured questionnaire to obtain demographic and socioeconomic data and information about health status and risk factors related to vitamin D insufficiency. Moreover, serum 25(OH)D was measured by the Abbott Chemiluminescence Immunoassay Analyzer (ARCHITECT i1000SR) to establish and provide reference values.
The mean 25(OH)D serum level was 13.4 ng/mL (5th–95th percentile, 12.34–14.5). Notably, 92% of the studied sample had 25(OH)D serum levels below 30 ng/mL, 79.3% below 20 ng/mL, and 61% below 12 ng/mL.
The younger group (18–28 years of age) was reported to have a significantly lower serum 25(OH)D level compared to the other three different age groups (29–40), (41–50), and (51–65) years old.
Our results also showed that serum 25(OH)D level was not significantly associated with gender, obesity (BMI), sun cream use, sun exposure, or wearing a hijab (head cover).
However, no significant differences in serum 25(OH)D levels were reported among individuals consuming cheese, yogurt, eggs, fish, milk, bread, and nuts.
In conclusion, according to the lack of correlated evidence of major skeletal and non-skeletal disease conditions with vitamin D levels that are recommended as optimal (≥20 ng/mL or even ≥30 ng/mL), and in light of our study to establish vitamin D reference levels in healthy adults, we recommend considering levels below 20 ng/mL and close to 14 ng/mL as sufficient serum 25(OH)D levels for the general population in the West Bank society.
However, our study sample is limited by the small number of participants; hence, further investigation and research are needed to establish more comprehensive and inclusive conclusions regarding reference levels and related factors.
