Lack of essential vitamins and minerals common in people with type 2 diabetes, reveals research

Micronutrient deficiency, whereby levels of vitamins and minerals essential for healthy bodily function are far too low, is common in people with type 2 diabetes, finds a pooled data analysis of the available evidence, published in the open access journal BMJ Nutrition Prevention & Health.

A lack of vitamin D is the most common ‘missing’ micronutrient, overall, the findings indicate, with women at greater risk than men of these deficiencies, dubbed 'hidden hunger.'

Genetic predisposition, various environmental factors, sedentary lifestyle, an unhealthy diet and obesity are risk factors for the disease, explain the researchers. And previously published research suggests that micronutrients have a key role in the development of type 2 diabetes, by potentially affecting glucose metabolism and insulin signalling pathways.

In a bid to try and quantify the global prevalence of micronutrient deficiency in people with the condition, the researchers scoured research databases for relevant studies, with the aim of pooling the data.

Their analysis included 132 studies, involving 52,501 participants, and published in several languages between 1998 and 2023. With the exception of 3 studies, the rest were hospital based.

The pooled data analysis showed that the prevalence of micronutrient deficiency (vitamins, minerals, and electrolytes) among people with type 2 diabetes varied around the world, possibly because of diverse dietary habits, lifestyle choices, and cultural practices, suggest the researchers.

But, overall, the global prevalence was 45%-40% in those with complications of their disease.

A very low level of vitamin D was the most common micronutrient deficiency, affecting 60.5% of those with type 2 diabetes. But magnesium deficiency was also common, affecting 42%, while the prevalence of iron deficiency was 28%. The global prevalence of B12 deficiency was 29%, and higher, still, among patients taking metformin.

Further stratification of the pooled data showed that prevalence was higher in women with the condition than in men at nearly 49%, and highest among patients in the Americas (54%).

Most of the included studies were cross sectional, making it difficult to establish causality, nor was it clear whether the micronutrient deficiency preceded poor glycaemic control or was a consequence of it, caution the researchers.

And as there are no valid population based studies looking at micronutrient deficiency, it’s impossible to draw comparisons between patients with type 2 diabetes and the general population, they add.

“This systematic review exemplifies the double burden of malnutrition in action, whereby nutritional deficiencies and diet-related non-communicable diseases, such as type 2 diabetes, co-exist,” comments Shane McAuliffe, Visiting Senior Academic Associate, NNEdPro Global Institute for Food, Nutrition and Health, which co-owns the journal.

“The treatment of type 2 diabetes often tends to focus on energy metabolism and macronutrients, but the identification of a higher prevalence of specific micronutrient deficiencies in those affected is a reminder that optimising overall nutrition should always be a priority.

“The findings should help to focus research and policy initiatives aimed at furthering our understanding of the causes and effects of these deficiencies and the potential for targeted and tailored interventions.”

Reference:

Burden of micronutrient deficiency among patients with type 2 diabetes: systematic review and meta-analysis, BMJ Nutrition Prevention & Health (2025). DOI: 10.1136/bmjnph-2024-000950