Study finds common vitamin may protect against deadly ‘silent killer’

It's hard to keep up with what's good for us and what's not in 2025.

While the antioxidants in chocolate can apparently help with your heart health, and a glass of wine can improve your gut, everything has to be done in moderation.

Even though some tell us to ditch our daily dose of coffee, even biohacker Bryan Johnson says a cup of joe can be good for our health.

The World Health Organization also made a shocking U-turn on the use of Ozempic, with a fierce debate on whether the benefits of skinny jabs outweigh the side effects.

It seems we can't do right for doing wrong, and it's increasingly hard to keep track of what we should and shouldn't be putting in our bodies.

However, just like coffee has been linked to helping lower the risk of atrial fibrillation, a new study suggests that an increased dose of a common household vitamin can reduce your risk of heart disease.

Even if there's the futuristic idea that AI can detect heart disease early, there's no escaping the fact that it's the biggest killer in the USA – responsible for around 700,000 deaths every year.

As heart disease is a major cause for concern, the notion that taking a simple vitamin can help steer us away from it is sure to be big news.

We all know getting a dose of vitamin D from sunlight is good for the body, with rays being synthesized through the skin like we're fleshy plants. In those winter months when the Sun is struggling to peek through the clouds, vitamin D can also be found in fatty fish like salmon, liver, egg yolks, and fortified foods, including some spreads and breakfast cereals.

When you've had enough of chugging orange juice, you could take a vitamin supplement to top up your vitamin D intake, and according to Heidi T May from Intermountain Health, there could be untold benefits.

The Independent explains how May and others behind the study are calling for specific vitamin D doses that are tailored to each patient.

Presented at the American Heart Association’s Scientific Sessions 2025, May said: "Our results suggest that targeting vitamin D supplementation based on blood levels can significantly diminish the risk of subsequent heart attacks.

"This approach demands a personalised, vigilant clinical protocol that diverges from the traditional fixed-dose model."

The study maintains that the one-size-fits-all idea doesn't work anymore, saying that vitamin D supplementation should be monitored every three months.

Looking at 630 adult participants who'd be diagnosed with acute heart disease, Utah's Intermountain Medical Center in Utah covered a six-year period, with an average follow-up of four years. The study concluded that over 85% of them had 'suboptimal' vitamin D levels that sat below 40 nanograms per millilitre (ng/mL) of blood.

Splitting the group randomly into two, scientists gave half standard care without managed vitamin D levels, while the others were given serial blood testing, which ensured their vitamin D levels sat above the 40 ng/mL threshold.

The treatment group boasted a 52% reduction in the risk of recurring heart attacks when compared to the control group.

Researchers called it one of the most significant findings in the field of vitamin D cardiovascular research. Still, they advised doctors to retain caution until it can be corroborated by peer-reviewed trials on a larger scale.