Burden of micronutrient deficiency among patients with type 2 diabetes: systematic review and meta-analysis

Background Micronutrient deficiencies are a significant issue worldwide, particularly in South Asia and sub-Saharan Africa. These deficiencies can impact glucose metabolism and insulin signalling pathways, potentially leading to the onset and progression of type 2 diabetes (T2D). This study provides a comprehensive assessment of the burden of multiple micronutrient deficiencies among T2D patients to resolve conflicting evidence from previous studies that mainly focused on single micronutrients. Methods The systematic review followed PRISMA 2020 and Cochrane Handbook guidance. A comprehensive search covered Embase, ProQuest, PubMed, Scopus, Cochrane Library, Google Scholar, LILACS and grey literature. Data were extracted using a pre-piloted sheet. Meta-analyses were conducted in R (v4.3.2) with meta and metafor packages. Results The analysis included 132 studies with 52,501 participants. The pooled prevalence of any micronutrient deficiency (vitamins, minerals, electrolytes) was 45.30% (95% CI 40.35% to 50.30%) among T2D patients. Prevalence was higher in women (48.62%, 95% CI 42.55% to 54.70%) than in men (42.53%, 95% CI 36.34% to 48.72%). Vitamin D deficiency was most prevalent (60.45%, 95% CI 55% to 65%), followed by magnesium (41.95%, 95% CI 27% to 56%). Vitamin B12 deficiency was 28.72% (95% CI 21.08% to 36.37%) among those on metformin. Prevalence varied across WHO regions. Conclusions Micronutrient deficiencies are common in T2D, especially vitamin D deficiency. Women are more affected than men. As most studies were hospital-based, findings should be interpreted cautiously due to selection bias. Dietary diversity, lifestyle and cultural practices may contribute to geographic variation. Trial registration PROSPERO CRD42023439780.

Daya Krishan Mangal, Nida Shaikh, Himanshu Tolani, Diksha Gautam, Anuj Kumar Pandey, Yeshwanth Sonnathi, Shiv Dutt Gupta, Sanjay Kalra, Kamlesh Chand Sharma, Jagdish Prasad, Rajeev Tewari, Fahmina Anwar