Cholesterol supplement linked to rare but reversible eye damage at high doses, warns optician

But a large study of more than 25,000 patients investigating treatment with niacin in combination with cholesterol-lowering drugs found little added benefit compared with when statins were taken alone.

What’s more, the supplement appeared to be linked with concerning side effects like new-onset diabetes or worsening the condition of current diabetics.

But while niacin is essential for various bodily functions and poses no major risks at normal levels, it behaves differently to other supplements, warned dispensing optician at Feel Good Contacts, Krina Halai.

"Unlike other supplements such as vitamin B12, zinc, or omega-3 fatty acids, niacin has a smaller safety window," she told GB News.

"Extremely high doses of niacin can sometimes trigger a condition called niacin-induced maculopathy, causing fluid build-up in the macula and presenting symptoms of blurred or distorted vision.

"Niacin can disrupt the eye’s normal ability to function, creating small pockets of fluid, leading to areas of swelling in the macula.

"The link between high niacin dosage and eye health has been around for a number of years; however, retinal damage is extremely rare, and it is known to be reversible with early diagnosis and appropriate clinical management."

She points out that there is a common misconception that taking more of certain supplements is a good idea.

And with supplement use on the rise, the optician outlined key symptoms that could signal people to see a doctor.

"The key symptoms to look out for include sudden blurry or distorted vision, difficulty focusing, eyelid swelling and discomfort, dark patches in the central line of sight, and a sudden decline in vision in a matter of a few days."

The good news is that cases are extremely rare, and the condition can be reversed if caught early enough.

"Stopping niacin quickly is the key to reversing any changes in vision that have occurred."