NIN study links Vitamin D deficiency to heart cell damage

Vitamin D deficiency may damage the heart at the cellular level by disrupting the body’s natural defence mechanisms against stress and injury, researchers at the ICMR-National Institute of Nutrition (NIN) said.

Their latest study suggested that inadequate vitamin D levels can increase oxidative stress in heart tissue, trigger cellular stress responses and ultimately lead to the death of cardiac cells. The study, titled “Vitamin D mitigates oxidative and endoplasmic reticulum stress and protects cardiac tissue from apoptotic cell death in vivo and in vitro,” was conducted using rat models and laboratory-grown rat heart cells.

Researchers examined the effects of normal, low and deficient levels of dietary vitamin D and investigated whether the vitamin could protect heart cells from damage caused by oxidative stress. The findings showed that rats given food low in vitamin D showed significantly higher levels of oxidative damage in heart tissue. They also had lower levels of glutathione, a key antioxidant, and reduced activity of important antioxidant enzymes that help protect cells from damage caused by harmful molecules known as free radicals.

It was also found that vitamin D deficiency impaired the ‘Nrf2 pathway’, a critical cellular defence mechanism that helps the body counter oxidative stress. “We observed increased markers of endoplasmic reticulum (ER) stress, autophagy and apoptosis in vitamin D-deficient hearts,” said scientist and lead researcher Ayesha Ismail.

She explained that prolonged oxidative stress associated with inadequate vitamin D may set off a chain of cellular events that contribute to heart cell injury and death. Laboratory experiments on rat cardiac cells produced similar results.

When exposed to oxidative stress, the cells showed reduced survival and higher levels of cellular damage. However, treatment with the active form of vitamin D improved antioxidant responses and reduced markers of oxidative stress, ER stress and apoptosis, indicating a protective effect. The findings point to growing evidence that vitamin D plays a role beyond bone health and may also be important for maintaining healthy heart function.

However, ICMR-NIN director Bharati Kulkarnicautions against drawing direct conclusions for humans from the study. “This study indicates that adequate vitamin D may help cardiac cells cope with oxidative stress and limit stress-related cellular damage. However, since the findings are based on animal and cell models, further investigations in humans are needed,” she added. The research, published in the international journal Steroids, according to a press release.