Is diabetes medication harming your nerves? Dr V. Mohan on the risks of vitamin B12 deficiency

Every year, millions of Indians managing diabetes diligently track their blood sugar, watch their diet, and take their medications on time. What most of them don’t know is that the very disease they are managing, and in some cases, the medicines keeping it in check, may be quietly destroying something they cannot see or feel until it’s too late for their nerves. And the damage, when it comes, arrives without warning.

How does diabetes hurt your nerves?

Diabetes is usually understood in terms of blood sugar. What it does to the nerves, however, is less talked about and often more serious. Over time, consistently high blood sugar begins to damage the body in less visible ways. It affects the tiny blood vessels that supply the nerves and disrupts how nerve signals travel through the body. This can lead to a condition called diabetic peripheral neuropathy, which causes nerve damage, most commonly in the hands and feet. The early signs are easy to miss. The most common symptoms are a faint numbness, burning, and tingling in the hands and feet that seem to come and go.

What nutrients do your nerves need?

What most people with diabetes don’t realise is that the commonly prescribed medications can reduce vitamin B12 levels over time, with long-term users showing about 19% lower levels than non-users, according to the Brain Disorders journal. In a country where 51% of the population is already B12-deficient, according to the European Journal of Cardiovascular Medicine, this isn’t a small concern; it exacerbates an existing problem and increases the risk.

Vitamin B12 helps maintain myelin sheath, the protective layer around nerve fibres that allows signals to travel smoothly through the body. When B12 levels drop, this layer begins to break down, and symptoms such as numbness, burning, tingling in the hands and feet, fatigue, memory lapses, and mood changes may appear. If left untreated, this can lead to irreversible nerve damage.

The challenge with both diabetic neuropathy and B12 deficiency is that neither is loud in its early stages. The Vitamin B12 deficiency symptoms to watch for include tingling or numbness, unusual fatigue, memory lapses, low mood, and a burning sensation in the feet. This distinction matters because B12 deficiency, caught early, is treatable. The damage is not always reversible once it progresses.

What actually helps?

The form of vitamin B12 that is most important for nerve health is methylcobalamin. This active form helps repair and protect nerves. Studies show that people with neuropathy who take it can see noticeable improvement in symptoms, with some recovering function within a month. It is widely available as an oral supplement and commonly used in nerve care.

For people already managing the daily discomfort of peripheral neuropathy, such as persistent burning and tingling, topical formulations containing 0.075% capsaicin, menthol, eucalyptus, and camphor can help bridge the gap, according to the Journal of the Association of Physicians of India. Over-the-counter nerve pain relief creams, including creams specifically formulated for numbness, burning, and tingling in hands and feet, offer localised relief for sensitised nerve pain.

Can diabetes cause nerve damage?

Nerve damage in diabetes is common. It is not inevitable. The right supplements, the right topical support, and a timely conversation with your doctor can change the trajectory of something most people assume they have to live with. Science exists. The solutions are accessible. The only thing left is the timely decision to act.