Vitamin D and suicidality: a Chinese early adolescent cohort and Mendelian randomization study

Authors：Yuan M, Li Y, Chang J, Zhang X, Wang S, Cao L, Li Y, Wang G, Su P.

Source：Epidemiol Psychiatr Sci. 2023 Aug 9;32:e52.

DOI: 10.1017/S2045796023000665.

Abstract：

Aims: Previous cross-sectional and case-control studies have proposed that decreased vitamin D levels are positively correlated with the risk of suicidality in adults. However, limited studies have examined the association between vitamin D and suicidality in adolescents. This study aimed to investigate the relationship between serum vitamin D and suicidality risk among early adolescents.

Methods: Data were obtained from a Chinese early adolescent cohort. In this cohort, seventh-grade students from a middle school in Anhui Province were invited to voluntarily participate in the baseline assessments and provide peripheral blood samples (in September 2019). The participants were followed up annually (in September 2020 and September 2021). Serum 25-hydroxyvitamin D [25(OH)D] and vitamin D-related single-nucleotide polymorphisms at baseline were measured in November 2021. Traditional observational and Mendelian randomization (MR) analyses were performed to examine the relationship between serum 25(OH)D at baseline and the risk of baseline and incident suicidality (i.e., suicidal ideation [SI], plans and attempts).

Results: Traditional observational analysis did not reveal a significant linear or non-linear association of serum 25(OH)D concentration with the risks of baseline and 2-year incident suicidality in the total sample (P > .05 for all). Sex-stratified analysis revealed a non-linear association between the 25(OH)D concentration and the risk of baseline SI in women (Poverall = .002; Pnon-linear = .001). Moreover, the risk of baseline SI in the 25(OH) insufficiency group was lower than that in the 25(OH) deficiency group in the total sample (odds ratio [OR] = 0.69, 95% confidence interval [CI] = 0.51-0.92, P = .012). This difference remained significant in women (OR = 0.59, 95% CI = 0.40-0.87, P = .008) but not in men (OR = 0.78, 95% CI = 0.53-1.15, P = .205). Additionally, both linear and non-linear MR analyses did not support the causal effect of serum 25(OH)D concentration on the risk of baseline, 1-year and 2-year incident suicidality (P > .05 for all).

Conclusions: This study could not confirm the causal effect of vitamin D on suicidality risk among Chinese early adolescents. Future studies must confirm these findings with a large sample size.

摘要：

目的：以往的横断面和病例对照研究表明，维生素D水平降低与成人自杀风险呈正相关。然而，有限的研究调查了维生素D与青少年自杀之间的关系。本研究旨在探讨早期青少年血清维生素D与自杀风险的关系。

方法：数据来自中国早期青少年队列。在该队列中，邀请安徽省某中学七年级学生自愿参与基线评估并提供外周血样本(2019年9月)。每年(2020年9月和2021年9月)对参与者进行随访。于2021年11月测定血清25-羟基维生素D [25(OH)D]和维生素D相关单核苷酸多态性。采用传统的观察性和孟德尔随机化（MR）分析，研究基线时的血清25（OH）D与基线风险和事件自杀倾向（即自杀意念[SI]、计划和企图）之间的关系。

结果：传统的观察分析没有显示总样本中血清25（OH）D浓度与基线风险和2年自杀倾向有显著的线性或非线性关联（均为P>.05）。性别分层分析显示25(OH)D浓度与女性基线SI风险之间存在非线性关联(overall = 0.002;非线性= .001)。此外，在总样本中，25(OH)不足组的基线SI风险低于25(OH)缺乏组(优势比[OR] = 0.69, 95%可信区间[CI] = 0.51-0.92, P = 0.012)。这种差异在女性中仍然显著(OR = 0.59, 95% CI = 0.40-0.87, P = 0.008)，但在男性中不显著(OR = 0.78, 95% CI = 0.53-1.15, P = 0.205)。此外，线性和非线性MR分析均不支持血清25(OH)D浓度对基线、1年和2年自杀事件风险的因果影响(均P > 0.05)。

结论：本研究不能证实维生素D对中国早期青少年自杀风险的因果影响。未来的研究必须用更大的样本量来证实这些发现。