Vitamin D2026-06

Vitamin D attenuates Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and downregulates hepatic gluconeogenesis in obesity.

Cordeiro Maiara M, Lucredi Naiara Cristina, Pateis Vanesa Oliveira, Souza Gustavo Henrique et al. — The Journal of nutritional biochemistry

Summary

A study in obese rats found that vitamin D supplementation improved a condition called Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), often known as fatty liver disease. It helped reduce fat accumulation in the liver and improved the body's ability to manage blood sugar, suggesting a potential role for vitamin D in addressing these obesity-related health issues.

AI-generated summary — read the original

Key points

Vitamin D supplementation helped reduce fatty liver disease (MASLD) in obese rats.
It improved the body's ability to manage blood sugar by reducing sugar production in the liver.
The treatment also led to better insulin sensitivity and glucose tolerance in the obese rats.
These results suggest vitamin D may have therapeutic potential for obesity-related metabolic problems.

What the study looked at

This research investigated whether vitamin D supplementation could improve Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), commonly known as fatty liver disease, and reduce excessive sugar production in the liver, both of which are common issues in obesity. Scientists used Wistar rats that were made obese by feeding them a "cafeteria diet," which mimics unhealthy human eating patterns. These obese rats were then divided into groups, with some receiving weekly vitamin D supplements and others not. Researchers monitored their food intake, body weight, liver health, blood sugar control, and markers of inflammation and oxidative stress over several weeks. What it found: The study found that vitamin D supplementation significantly reduced body weight gain and improved insulin resistance and glucose tolerance in the obese rats. Crucially, it decreased fat accumulation in the liver (MASLD) and lowered the liver's excessive production of sugar. These beneficial effects were also linked to reduced inflammation and oxidative stress in the liver. The findings suggest vitamin D could play a role in managing obesity-related liver and blood sugar problems.

Dietary takeaway

While this study was conducted in rats, it suggests that maintaining adequate vitamin D levels might be beneficial for individuals at risk of or living with obesity-related fatty liver disease and blood sugar issues. Foods like fatty fish (salmon, mackerel), fortified milk, and some mushrooms are good sources of vitamin D. However, remember that findings from animal studies don't always translate directly to humans, and more research is needed to confirm these effects in people.

Abstract

Metabolic dysfunction-associated steatotic liver disease (MASLD) is often linked to vitamin D deficiency. Insulin resistance (IR) plays a central role in MASLD and is tied to an abnormal activation of hepatic gluconeogenesis, contributing to the hyperglycemia found in this condition. This study evaluated whether vitamin D supplementation improves MASLD and reduces hepatic glucose production in cafeteria diet-induced obese rats. Inflammation, oxidative stress, and IR were additionally assessed both systemically and in the liver. Gluconeogenic and glycogenolytic fluxes were measured in perfused livers. Wistar rats received a cafeteria or standard diet for 60 days and remained on these diets for another 5 weeks; during this period, a subgroup in each condition received weekly vitamin D (5,600 IU/kg) by oral gavage. The cafeteria diet promoted obesity, MASLD, IR, oxidative stress and inflammation. Obese rats displayed elevated hepatic gluconeogenesis from lactate and intensified glycogenolysis and glycolysis. Vitamin D supplementation reduced food intake and body weight gain and improved IR and glucose tolerance, changes accompanied by lower hepatic steatosis. The treatment decreased hepatic mRNA expression of NF-κB, TNFα, and IL-6, and increased Nrf2 expression. It also elevated vitamin D receptor, sirtuin-1 and FGF21/β-klotho axis expression, findings associated with higher IRS-2 and Nrf2 expression and lower NF-κB expression. Vitamin D reduced the elevated gluconeogenesis and glycogenolysis in obese rats, as determined by direct metabolic flux measurements, likely due to improvements in IR/MASLD. The results support the therapeutic potential of vitamin D in MASLD induced by a cafeteria diet that resembles obesogenic human dietary patterns and suggest benefits for controlling hyperglycemia in obesity.

View on PubMed →DOI: 10.1016/j.jnutbio.2026.110450