Vitamin D breakthrough: Supplement 'could reverse years of ageing' and lower dementia risk

Taking a simple daily Vitamin D supplement could help turn back the clock on biological ageing, according to groundbreaking new research.

In a major clinical trial, scientists found that adults who took vitamin D every day experienced significantly less age-related damage to their DNA - a change linked to serious illnesses including Alzheimer's disease and cancer, reported

The study concluded that a four-year course of vitamin D supplementation "prevented the equivalent of nearly three years of ageing".

The findings, published in the American Journal of Clinical Nutrition, are based on a large trial involving 1,054 adults aged 50 and over. Participants were either given a placebo or a daily vitamin D pill.

Researchers monitored the length of each participant's telomeres - the protective caps on the ends of DNA strands that gradually shorten with age. Shortened telomeres are a known indicator of biological ageing and have been associated with cancer, heart disease, and cognitive decline.

"Compared with taking a placebo, taking vitamin D3 supplements significantly reduced telomere shortening over four years," the study confirmed.

The scientists said vitamin D represents a "promising strategy to counter biological ageing" and may also help reduce the risk of diseases such as dementia.

Often likened to the plastic tips on shoelaces, telomeres shield DNA from damage. But over time, these telomeres shorten, leaving DNA exposed - impairing the body's ability to regenerate cells and making people more vulnerable to disease.

The Vital trial, which yielded the findings, was led by researchers at Mass General Brigham, a prestigious research centre affiliated with Harvard University.

JoAnn Manson, the lead researcher, described the trial as "the first large-scale and long-term randomised trial to show that vitamin D supplements protect telomeres and preserve telomere length."

"This is of particular interest because Vital had also shown benefits of vitamin D in reducing inflammation and lowering risks of selected chronic diseases of ageing, such as advanced cancer and autoimmune disease," she added.

Participants were given a daily dose of 2,000 IU (50 micrograms) of vitamin D3.

Haidong Zhu, one of the study's authors, said: "Our findings suggest that targeted vitamin D supplementation may be a promising strategy to counter a biological ageing process, although further research is warranted."

Previous research has already shown that vitamin D may lower the risk of developing dementia.

Vitamin D is produced naturally in the body when skin is exposed to sunlight. It can also be found in foods such as oily fish, liver, and red meat. While most people obtain enough vitamin D during the sunnier months, the NHS recommends that everyone consider taking a daily supplement during autumn and winter - especially those who spend little time outdoors.