7 signs of vitamin B12 deficiency and what your body is trying to tell you before it worsens

Vitamin B12 deficiency symptoms can begin quietly, often serving as the body’s subtle call for an essential nutrient also known as cobalamin.

This vital B vitamin plays a crucial role in maintaining the health of both nerve and blood cells, serving as a vital building block for your body’s systems.

However, because the human body cannot produce vitamin B12 on its own, people must obtain it from external sources, such as food, specifically animal products like meat, dairy, and eggs, or from dietary supplements.

Despite being water-soluble, meaning the body eliminates any excess amounts through urine, B12 can be stored in the liver for up to five years, according to WebMD. Due to this storage capacity, a deficiency may not be apparent for a long time.

But experts warn that over time, low intake, poor absorption, or certain underlying health conditions can slowly and silently drain the body’s supply, leading to serious health complications that impact everything from your mood to your memory.

This health challenge is widespread among older adults. Studies suggest that up to 20% of people over the age of 60 in the United States and the United Kingdom may be deficient in vitamin D.

In many cases, when vitamin B12 levels are low, the aging process itself can make it harder for the body to absorb B12 from food. The use of certain medications and limited diets can also significantly raise the risk.

Yet, this issue is not limited to seniors. Children, younger adults, and even people who are pregnant or nursing can develop low levels of the vitamin, Healthline noted.

Because the warning signs are often vague and easy to miss, like simple fatigue or a mild headache, B12 deficiency is frequently misdiagnosed or overlooked.

As a result, experts emphasize the importance of regular health checks and proper testing to detect the problem early and prevent long-term health issues.

Nine critical vitamin B12 deficiency symptoms that signal trouble

When vitamin B12 levels are low, the body sends out several warning signals.

Here are nine of the most reported symptoms of Vitamin B12 deficiency, along with how this deficiency can be addressed to achieve a positive outcome.

1. Fatigue: More Than Just Being Tired

Feeling constantly tired could be more than a busy schedule; it might signal a B12 deficiency. Your body needs vitamin B12 for cells to work properly, and without enough, your red blood cell production can slow down. This can reduce oxygen delivery throughout the body and cause megaloblastic anemia, a condition in which red blood cells become large, abnormal, and immature. With less oxygen reaching your cells, your energy naturally drops, leaving you feeling drained.

2. Pale or Yellow Skin

A lack of B12 can cause your skin to look unusually pale, similar to the appearance of iron deficiency anemia. This happens because your body isn’t producing enough fully matured red blood cells. In some cases, a B12 deficiency can also cause jaundice, resulting in the skin and whites of the eyes turning yellow due to high bilirubin levels.

3. Headaches

Headaches are a common symptom of Vitamin B12 deficiency in both adults and children. A 2019 study of 140 people, half of whom had migraines, found that those with the highest B12 levels were 80% less likely to suffer migraines than participants with the lowest B12 levels. Research is ongoing to see if increasing B12 can help ease migraine symptoms.

4. Depressive Symptoms and Mental Health

Low B12 levels can increase the risk of depression. This is linked to elevated levels of homocysteine, a sulfur-containing amino acid, which may damage DNA, increase oxidative stress, and harm cells. A 2020 study of 132 children and teens found that those with depression had lower B12 levels and higher homocysteine levels than those without depression. In addition to depression, low B12 may contribute to other mental health issues, including psychosis and mood disorders.

5. Gastrointestinal Issues

B12 deficiency can affect digestion, causing symptoms such as diarrhea, nausea, constipation, bloating, or gas. These symptoms may occur in both children and adults.

6. Difficulty Concentrating and Mental Impairment

A B12 deficiency can impact the central nervous system, leading to feelings of being “foggy-headed” and difficulty concentrating. Studies link low B12 to worsened mental function in older adults. A 2020 study treated 202 people with mild cognitive impairment and low or low-normal B12 levels for three months. After B12 therapy, 84% reported improved focus, better memory, and reduced forgetfulness, demonstrating the positive effects of proper B12 levels on brain health.

7. Pain and Inflammation of the Mouth and Tongue

Glossitis, an inflamed and painful tongue, can be a sign of low B12 levels. It may be accompanied by stomatitis, which causes sores and inflammation in the mouth. While common in B12-related anemia, these symptoms can also appear without anemia, making them early signs of a deficiency.

8. Paresthesia in Hands and Feet

People with B12 deficiency often experience tingling, burning, or a pins-and-needles sensation in the hands or feet, a condition called paresthesia. These symptoms can mimic diabetic neuropathy, especially in people taking metformin, a medication that can reduce B12 absorption. Experts recommend regular screening for those at risk to avoid misdiagnosis.

9. Other Neurological and Physical Symptoms

B12 deficiency can also cause:

• Muscle cramps and weakness: Low B12 affects motor and sensory nerves, leading to muscle discomfort.
• Impaired coordination: Ataxia, or balance problems, may make walking and movement difficult.
• Erectile dysfunction: Men may experience sexual health issues linked to elevated homocysteine.
• Vision disturbances: Damage to the optic nerve can affect sight.

Best sources of vitamin B12 for a healthier you

To prevent and treat these uncomfortable issues, knowing the best sources of vitamin B12 is key.

The good news is that B12 is readily available through food and supplements, says the Cleveland Clinic.

The best sources of vitamin B12 include:

Animal food products, including fish, milk, dairy products, eggs, poultry, and red meat, all contain vitamin B12.

Fortified foods: These are foods that have vitamins and nutrients added to them that they don’t naturally have. Fortified foods include certain breakfast cereals, nutritional yeast, plant milk, and certain breads. You can check the food label to see if a food has been fortified with vitamin B12.

Vitamin B12 dietary supplements: Many multivitamins have vitamin B12. Some supplements only contain B12. Consult with your healthcare provider or pharmacist to determine the best supplement for your specific needs.

Why strict diets risk vitamin B12 deficiency symptoms: The plant-based challenge

A major group susceptible to B12 deficiency includes strict vegans or vegetarians, says Power of Positivity.

Unlike many other vitamins, B12 is not often found naturally in plants. This presents a unique challenge in finding reliable sources.

One widely accepted solution is to use fortified products, such as fortified soy or nut milk.

Interestingly, vitamin B12 can be produced by microorganisms, such as bacteria and fungi. Since certain bacteria can be found in the soil, foods that come from the soil may naturally have small levels of B12.

Experts caution that scrubbing vegetables too vigorously might remove this beneficial bacteria.

For those seeking natural food options that contain some B12, mushrooms and fermented foods, such as tempeh, are noted.

Nori, a type of toasted seaweed, can also provide a B12 boost. Nutritional yeast is another good supplemental source for vegetarians.

Managing and Treating Vitamin B12 Deficiency

The good news is that treating a B12 deficiency is usually simple: it’s all about increasing your vitamin B12 levels.

Doctors often prescribe cyanocobalamin, a man-made form of B12. Treatment can take several forms, including oral pills, injections, or even a nasal spray or gel.

Additionally, incorporating more B12-rich foods into your diet, such as meat, fish, eggs, and dairy, can help restore healthy levels. The duration of treatment needed depends on the cause of the deficiency.

Some people may only need therapy until their levels return to normal, while others may require ongoing B12 support for life.

Beyond the fatigue: The positive power of B12

When your B12 levels are healthy, the positive impact is widespread:

Bone and Red Blood Cell Health: You need B12 to make healthy red blood cells, white blood cells, and platelets. Several studies have linked B vitamins, including B12, to a lower risk of osteoporosis. This disease weakens your bones and increases the risk of hip fractures.

Vision, Mood, and Memory: While a rare condition called optic neuropathy can occur when B12 levels are extremely low, correcting these levels can have a positive impact on cognitive function. One study found that when people with mild cognitive issues and low levels of B12 were given B12 vitamins, most of them showed improved cognitive symptoms. This highlights B12’s role in a sharp, clear mind.

Better Energy Levels: While B12 supplements don’t benefit individuals who already have normal levels, studies indicate that they can help those who consistently feel tired. Your B12 levels are low; raising them to normal may provide a significant energy boost.

Protecting your health: Simple steps to prevent vitamin b12 deficiency

There are easy ways to help prevent vitamin B12 deficiency. Limiting alcohol is important, as drinking frequently can harm the digestive system and make it harder for your body to absorb B12. Managing any digestive conditions is also key—following your healthcare provider’s guidance can help keep absorption on track.

The main takeaway is that signs of low B12 can be subtle, so knowing what to look for and making smart dietary choices is essential. By understanding what happens when vitamin B12 levels are low and taking action, you can support your health and maintain a positive outlook.

Discover which foods can help prevent Vitamin B12 deficiency symptoms by watching this short Healthline video on crucial B12-rich foods.

Disclaimer: This article is for informational purposes only and is not intended to serve as a substitute for professional advice, diagnosis, or treatment. Always seek the guidance of a qualified expert or licensed professional with any questions or concerns you may have.