From back pain to numb hands: Rwandan woman discovers hidden Vitamin B12 deficiency

For years, Umuhuza Charmante lived with persistent pain that doctors struggled to explain. It started in her back, later moved to her knees and elbows, and eventually came with numbness in her hands.

After more than a decade of seeking answers, medical tests in August 2026 revealed that she had a very low level of vitamin B12.

Vitamin B12 is an essential nutrient involved in the normal functioning of the nervous system and brain, as well as the production of red blood cells. When the body lacks enough of it, the deficiency can cause neurological and blood related problems, among other symptoms.

A long search for answers

Umuhuza says her health problems began in 2011 with persistent back pain.

She sought treatment at the University Teaching Hospital of Kigali (CHUK), where she was told that she had low calcium levels and was given medication. But the pain persisted.

“I started experiencing back pain in 2011. I went to CHUK, where I was told that I had low calcium levels. I was given medication and tried to eat foods rich in calcium, but I did not recover.”

The pain eventually spread to her knees and elbows.

In 2019, the condition became more severe. She first went to Kacyiru Health Centre before being referred to Kacyiru Hospital and later to Rwanda Military Hospital in Kanombe.

She underwent medical imaging, but six months later, she was told that no problem had been found in her bones or joints.

Despite the results, the pain continued.

Pregnancy made the pain worse

In 2023, Umuhuza became pregnant, and the pain in her knees intensified.

She says she sometimes felt as though her knees were being squeezed, making it difficult to climb stairs and, at times, to walk.

Because she was pregnant, doctors were cautious about prescribing medication that could potentially affect the unborn baby. She was advised to use knee braces and continue with exercises appropriate for pregnancy.

She also recalls receiving blessed water brought from Kibeho by a neighbour, after which she says her knee pain temporarily eased.

In 2024, she gave birth by caesarean section. Her attention then shifted to recovering from the surgery, while the longstanding pain remained largely unresolved.

The clue was vitamin B12

The situation changed in July 2026, when the pain in her elbows became worse and she began experiencing numbness and tingling in her hands.

The symptoms were sometimes so uncomfortable that she had to sleep with her arms stretched out.

In August, she consulted a doctor specialising in internal medicine, who ordered several tests.

When Umuhuza received the tests, she feared that they might reveal a serious illness.

Instead, Dr Rutanganda Eric explained that the tests had not identified a major problem, except for one significant finding: her vitamin B12 level was extremely low.

“I could not imagine that vitamin B12 deficiency could cause all those pains.”

The doctor also asked whether she had been experiencing memory problems.

She realised that forgetfulness had become increasingly common.

He then asked about changes in her mood.

“I was surprised by the question, but I remembered that my husband often tells me that I have become short tempered and that I no longer speak calmly as I used to.”

What causes vitamin B12 deficiency?

Vitamin B12 is naturally found mainly in animal source foods, including meat, fish, poultry, eggs, milk and dairy products such as yoghurt and cheese.

Umuhuza says her doctor explained the importance of incorporating such foods into her diet.

“Of all the foods he mentioned, I told him that apart from fish, I do not like any of them. But I told him that I would try to eat them.”

She was prescribed vitamin B12 tablets. Her doctor also explained that injections may be used when rapid replacement is needed or when the deficiency is severe.

Because she is afraid of injections, Umuhuza opted for tablets and was advised to return for further assessment if she did not improve.

More than tiredness

Vitamin B12 deficiency can develop gradually, meaning that some people may live with symptoms for months or even years before the underlying cause is identified.

Symptoms can include persistent fatigue and weakness, dizziness, shortness of breath when anaemia is present, numbness or tingling in the hands and feet, balance problems, memory difficulties, poor concentration and mood changes.

Some people may also develop a sore or red tongue and mouth ulcers.

Health professionals warn that prolonged, untreated vitamin B12 deficiency can affect the nervous system and cause nerve damage. Some neurological problems may become difficult to reverse if treatment is delayed.

For people experiencing persistent or unexplained symptoms such as numbness, tingling, unusual fatigue, memory problems or balance difficulties, medical evaluation is important.

Umuhuza’s experience illustrates how symptoms that appear unrelated can sometimes have a common underlying cause and why persistent health problems may require further investigation even when initial tests appear normal.