Controversial supplement may not be so bad after all — but only in these cases

A OK?

Beta-carotene is a red-orange pigment found in many fruits and vegetables. The body converts it into vitamin A, which is vital for good vision, a strong immune system, glowing skin and cellular processes like reproduction and growth.

Most healthy individuals get enough vitamin A from their diet, but those with certain medical conditions may benefit from beta-carotene supplementation to prevent vitamin A deficiency.

The problem is that large doses of beta-carotene supplements can be harmful, especially for smokers and people exposed to asbestos, because studies have shown they can increase the risk of lung cancer.

In a twist, new research out of UC San Diego suggests that excess beta-carotene supplementation may not hurt people who are seriously ill with cancer or heart disease.

The phenomenon is called “Cuomo’s Paradox” for biomedical scientist Raphael Cuomo, a professor at UCSD’s School of Medicine.

His theory proposes that things that experts have warned are detrimental — like obesity, elevated cholesterol and certain antioxidant supplements — can actually be harmless or even helpful for cancer or cardiovascular disease patients.

“Under Cuomo’s Paradox, a nutrient that seems protective before disease can fail to help (or even hurt) once serious illness enters the picture,” Cuomo told The Post.

“A textbook example of Cuomo’s Paradox, beta-carotene can be risky in high doses for healthy populations, while studies in sick populations have not linked it to shorter survival.”

Essentially, the dietary or lifestyle choices that help you avoid disease might not be the best approach once serious disease strikes and vice versa.

Cuomo pointed out that several million people have advanced cancer or heart disease.

He recommends that clinicians individualize recommendations for patients rather than copy standard prevention rules. 

His findings were published this month in the Journal of Nutrition.

As research continues, you should consult with your doctor before taking beta-carotene supplements.

Experts generally recommend consuming beta-carotene from food sources.

Carrots, sweet potatoes, other orange and yellow produce and dark leafy greens like spinach contain beta-carotene, a form of vitamin A known as provitamin A.

The other form of vitamin A — preformed vitamin A or retinol — is primarily found in animal-based foods such as liver, fish, dairy products and eggs.

Beta-carotene supplementation may be helpful for people with celiac disease, cystic fibrosis, sun sensitivity, vision conditions, malnutrition or trouble absorbing vitamin A.

Symptoms of deficiency include night blindness, reproductive issues, dry, scaly skin and chest infections.

About 75% of Americans take a dietary supplement, according to government data. Vitamin A, in its various forms, is a common ingredient in supplements.

After researchers observed that vitamin A possesses anti-cancer properties, there was a lot of optimism that beta-carotene supplements would be a magic bullet in preventing cancer.

But those hopes were dashed in the 1990s, when studies suggested that not only did beta-carotene supplements not have a protective effect, but they actually increased the risk of lung cancer in smokers.

Beta-carotene is an antioxidant. Under certain circumstances, like high oxygen tension in the lungs of smokers, beta-carotene can increase oxidative stress rather than reduce it.

Now, the US Preventive Services Task Force (USPSTF) recommends against taking beta-carotene supplements for the prevention of cardiovascular disease or cancer.