Aljefree Najlaa M, Lee Patricia, Ahmed Faruk
Public Health, School of Medicine and Menzies Health Institute Queensland, Griffith University, Building G01, Room 3.30, Gold Coast campus, Gold Coast, QLD, 4222, Australia.
Department of Medical Research, China Medical University Hospital, China Medical University, Taiwan, Taiwan.
BMC Public Health. 2017 Mar 16;17(1):266. doi: 10.1186/s12889-017-4183-1.
Vitamin D deficiency is prevailing in Saudi Arabia. Recent national data indicated an inverse association between vitamin D status and coronary heart disease (CHD), which increases concerns about vitamin D deficiency as a serious public health problem. Therefore, the current study aimed to investigate whether knowledge, attitudes and behaviors related to vitamin D contribute to the prevalence of vitamin D deficiency among adults with and without CHD in Saudi Arabia.
This case-control study consisted of 130 CHD cases and 195 matched controls. The study subjects were recruited from three hospitals in Saudi Arabia. Structured interviews were completed to collect data on participants' socio-demographics, knowledge about vitamin D, attitudes toward sun exposure, and behaviors related to vitamin D. Also, serum vitamin D levels were measured.
Severe vitamin D deficiency [serum 25(OH)D < 10 ng/mL] was more prevalent in the CHD cases than in the controls (46% and 3%, respectively). The total knowledge score was higher in the controls than in the cases [2.5 (±1.8) and 1.6 (±2.2), respectively]. The cases had better attitudes toward sun exposure compared to the controls (p = 0.001); however, the controls had better attitudes toward vitamin D compared to the cases (p = 0.001). The controls had a higher consumption of multivitamin supplements than the cases (6.7% and 0.8%, respectively; p = 0.010). Similarly, the controls had a higher consumption of butter (p = 0.001), oily fish (p = 0.004), and liver (p = 0.003) than the cases; however, the cases had a significantly higher intake of milk (p = 0.001). A multivariate logistic regression showed that vitamin D deficiency [25(OH)D < 20 ng/mL] was associated with low levels of knowledge about vitamin D, with an odds ratio of 1.82 (95% CI: 1.08-3.06, P = 0.024). Vitamin D deficiency was also associated with low intake of vitamin supplements, with an odds ratio of 4.35 (95% CI: 2.12-8.92, P < 0.001).
The present study revealed that low levels of knowledge about vitamin D and low consumption of vitamin supplementation, including vitamin D, calcium, multivitamin, and calcium supplements with vitamin D, may have contributed to the higher prevalence of vitamin D deficiency among the CHD cases than among the controls. Further studies using a qualitative approach are crucial to explore the underlying reasons for low knowledge about vitamin D and behaviors related to vitamin D including the intake of vitamin supplementation that may contribute to the high burden of vitamin D deficiency in the country.
维生素D缺乏在沙特阿拉伯普遍存在。近期的全国数据表明维生素D水平与冠心病（CHD）之间存在负相关，这增加了人们对维生素D缺乏作为一个严重公共卫生问题的担忧。因此，本研究旨在调查与维生素D相关的知识、态度和行为是否导致沙特阿拉伯患有和未患有冠心病的成年人中维生素D缺乏的流行。
本病例对照研究包括130例冠心病患者和195例匹配的对照。研究对象来自沙特阿拉伯的三家医院。通过完成结构化访谈来收集参与者的社会人口统计学数据、关于维生素D的知识、对阳光照射的态度以及与维生素D相关的行为。此外，还测量了血清维生素D水平。
严重维生素D缺乏[血清25(OH)D < 10 ng/mL]在冠心病患者中比在对照组中更普遍（分别为46%和3%）。对照组的总知识得分高于病例组[分别为2.5（±1.8）和1.6（±2.2）]。与对照组相比，病例组对阳光照射的态度更好（p = 0.001）；然而，与病例组相比，对照组对维生素D的态度更好（p = 0.001）。对照组服用多种维生素补充剂的比例高于病例组（分别为6.7%和0.8%；p = 0.010）。同样，与病例组相比，对照组食用黄油（p = 0.001）、油性鱼类（p = 0.004）和肝脏（p = 0.003）的比例更高；然而，病例组牛奶摄入量显著更高（p = 0.001）。多因素逻辑回归显示，维生素D缺乏[25(OH)D < 20 ng/mL]与维生素D知识水平低相关，比值比为1.82（95% CI：1.08 - 3.06，P = 0.024）。维生素D缺乏还与维生素补充剂摄入量低相关，比值比为4.35（95% CI：2.12 - 8.92，P < 0.001）。
本研究表明，对维生素D的低知识水平以及维生素补充剂（包括维生素D、钙、多种维生素和含维生素D的钙补充剂）的低摄入量可能导致冠心病患者中维生素D缺乏的患病率高于对照组。采用定性方法的进一步研究对于探索维生素D知识水平低以及与维生素D相关行为（包括维生素补充剂的摄入）的潜在原因至关重要，这些行为可能导致该国维生素D缺乏的高负担。
