A vegan diet is generally healthy, low in cholesterol and protective of heart disease, but its followers must take vitamin B12 supplements or risk a condition that causes permanent numbness in their hands and feet, experts say.

Axar.az reports citing The Guardian that most people get their vitamin B12 from milk, but the plant-based substitutes do not have high enough levels to protect adults and children from peripheral neuropathy, which is irreversible.

Sanders and Tim Key, professor of epidemiology and deputy director of the Cancer Epidemiology unit at Oxford University, have both researched the health of those who eat a vegan diet for many years. Key is himself a vegan – and takes vitamin B12 tablets regularly.