Seneviratne Ruwanika, Gunawardena Nalika, Arambepola Carukshi
Postgraduate Institute of Medicine, University of Colombo, Sri Lanka; No. 160, Professor Nandadasa Kodagoda Road, Colombo, 00700, Sri Lanka.
World Health Organization-South-East Asia Regional Office, World Health House, Indraprastha Estate, Mahatma Gandhi Marg, New Delhi, 110 002, India.
BMC Nutr. 2024 Aug 29;10(1):115. doi: 10.1186/s40795-024-00923-0.
Vitamin D deficiency (VDD) is conventionally associated with inadequate sunlight exposure. Ironically, recent evidence suggests a rising prevalence in urban areas of tropical regions like Sri Lanka, where comprehensive data are unavailable. This study aimed to estimate the prevalence of low vitamin D status in urban adults and its impact on serum calcium.
A population-based cross-sectional study was conducted among 1260 adults aged 35-74 years, living in Colombo, the most urban district in Sri Lanka. They were recruited from 63 administrative divisions, using multi-stage, probability-proportionate-to-size, cluster sampling. Non-fasting venous blood was collected without tourniquet. Low vitamin D (< 30.0 ng/mL), VDD (< 20 ng/mL) and vitamin D insufficiency (20.0-29.9 ng/mL) were determined using chemiluminescence assay method, and serum calcium using Calcium Gen2 reagent.
Among the population (53.3% females; mean age = 51.8 years), the prevalence of low vitamin D was 93.9% (95% CI: 92.5-95.2). This was primarily due to VDD (67.5%; 95% CI: 64.9.0-70.1%), with some insufficiency (26.4%; 95% CI: 24.0-28.9%). Most VDD cases (53.9.0%) were 'mild' (10.0- < 20.0 ng/mL) in severity, with fewer 'moderate' (12.8%) and 'severe' (0.8%) cases. Prevalence of VDD was highest in females, aged 35-44-years, living in 'highly urban' areas and of Tamil ethnicity. Further, VDD showed a decreasing trend with older age groups, while it was significantly more prevalent in females than males (72.6% vs. 61.7%; p < 0.01), across all age groups. Low serum calcium levels were observed in 9.8% of adults with low vitamin D, compared to 22.4% with normal vitamin D, implying that there could be factors other than vitamin D in maintaining serum calcium levels.
Colombo District, representing urban settings in Sri Lanka faces a high prevalence of low vitamin D, primarily VDD, with higher rates in females, younger individuals and highly urban areas. These findings challenge assumptions about tropical regions being guaranteed of optimal vitamin D levels; and underscore the need for national vitamin D supplementation and food fortification programs, especially in high-risk urban settings in South Asian countries like Sri Lanka.
传统上认为维生素D缺乏（VDD）与阳光照射不足有关。具有讽刺意味的是，最近的证据表明，在像斯里兰卡这样缺乏全面数据的热带地区城市，维生素D缺乏的患病率正在上升。本研究旨在估计城市成年人中维生素D水平低的患病率及其对血清钙的影响。
在斯里兰卡城市化程度最高的科伦坡地区，对1260名年龄在35 - 74岁的成年人进行了一项基于人群的横断面研究。采用多阶段、按规模比例概率抽样的方法，从63个行政区招募研究对象。不使用止血带采集非空腹静脉血。采用化学发光分析法测定低维生素D（<30.0 ng/mL）、维生素D缺乏（<20 ng/mL）和维生素D不足（20.0 - 29.9 ng/mL），使用钙Gen2试剂测定血清钙。
在研究人群中（女性占53.3%；平均年龄 = 51.8岁），低维生素D的患病率为93.9%（95%置信区间：92.5 - 95.2）。这主要是由于维生素D缺乏（67.5%；95%置信区间：64.9 - 70.1%），还有一些维生素D不足的情况（26.4%；95%置信区间：24.0 - 28.9%）。大多数维生素D缺乏病例（53.9%）为“轻度”（10.0 - <20.0 ng/mL），“中度”（12.8%）和“重度”（0.8%）病例较少。维生素D缺乏在居住在“高度城市化”地区、泰米尔族裔、年龄在35 - 44岁的女性中患病率最高。此外，维生素D缺乏在老年人群中呈下降趋势，而在所有年龄组中，女性的患病率显著高于男性（72.6%对61.7%；p < 0.01）。维生素D水平低的成年人中，9.8%的人血清钙水平低，而维生素D水平正常的成年人中这一比例为22.4%，这意味着在维持血清钙水平方面可能存在除维生素D之外的其他因素。
代表斯里兰卡城市环境的科伦坡地区面临着维生素D水平低的高患病率，主要是维生素D缺乏，在女性、年轻人和高度城市化地区患病率更高。这些发现挑战了关于热带地区能保证最佳维生素D水平的假设；并强调了国家维生素D补充和食品强化计划的必要性，特别是在像斯里兰卡这样的南亚国家的高风险城市地区。
