Vitamin B12 is an essential nutrient that plays many important roles in the body, including helping to make DNA and red blood cells and keeping the nervous system healthy. Some research has linked low levels of B12 to potential sleep disruptions. In this article, we’ll explore the connection between vitamin B12 and sleep, looking at the causes and symptoms of B12 deficiency and how it may impact sleep quality. We’ll also discuss how to test B12 levels and treatment options for improving levels.
What is vitamin B12 and why is it important?
Vitamin B12, also known as cobalamin, is a water-soluble essential vitamin that plays a role in many crucial processes in the body. It helps:
- Make red blood cells and DNA
- Maintain healthy nerve cells and neurotransmitters
- Process folate
- Metabolize carbohydrates, fats and proteins
We get B12 from animal-based foods or supplements, as it is not naturally present in plant foods. Good food sources include meat, fish, eggs and dairy products. The daily recommended intake is around 2.4 mcg for adults, higher for pregnant and breastfeeding women.
B12 is unique in that the body stores several years’ worth in the liver, so deficiency symptoms may not appear until stores have been depleted after a few years. Common causes of deficiency include:
- Pernicious anemia – an autoimmune condition where the body attacks cells in the stomach that help absorb B12 from foods
- Other malabsorption issues from digestive disorders, like Crohn’s disease
- Medications – acid reflux, diabetes and immune suppressing drugs
- Surgeries – weight loss, bowel or pancreas removal
- Being vegan or vegetarian if no supplements are taken
- Alcohol abuse
- Being over age 50 – reduced stomach acid secretion
Without enough B12, vital bodily processes start to suffer. Early deficiency can cause fatigue, weakness, constipation, loss of appetite, weight loss, numbness and tingling in extremities. It can also lead to neurological issues like depression, memory problems and dementia. Long term, severe deficiency can damage the nervous system.
How might low B12 impact sleep?
There are a few potential ways that insufficient B12 levels may disrupt sleep:
Anemia
One of vitamin B12’s main jobs is aiding in red blood cell formation. Without enough B12, fewer red blood cells can form, leading to a condition called anemia. Red blood cells carry oxygen, so with anemia, less oxygen circulates in the bloodstream to body tissues.
Even a mild level of anemia can cause daytime fatigue and sleepiness. More severe anemia can disrupt sleep, causing symptoms like:
- Restless legs syndrome
- Pfrequent nighttime awakenings
- Insomnia
- Hypersomnia – excessive daytime sleepiness
- Snoring and sleep apnea
Research indicates there is a higher prevalence of restless leg syndrome and sleep apnea among those with iron deficiency anemia.
Circadian Rhythm Disruption
The circadian rhythm is the body’s internal clock that regulates sleep/wake cycles. There are some links between B12 levels and circadian rhythms. Studies show many patients with B12 deficiency experience “delayed sleep phase syndrome” where the timing of the sleep/wake cycle is significantly delayed.
B12 is also vital for metabolizing melatonin and serotonin, neurotransmitters that control sleep/wake cycles. When B12 is low, levels of these hormones may fall out of balance, impairing circadian rhythms.
Neurologic Effects
B12 helps maintain the nervous system by forming the protective myelin sheath around nerves. When B12 drops, nerve functioning suffers. This can lead to:
- Numbness and tingling
- Muscle weakness and coordination issues
- Cognitive impairment – trouble concentrating, memory loss, brain fog
- Mood disorders – depression, irritability, anxiety
- Psychosis in severe cases
These effects may make it difficult to fall and stay asleep. The mood disorders associated with B12 deficiency are also strongly linked to sleep disruptions.
Sleep Apnea Risk
Those with an underactive thyroid (hypothyroidism) have a higher risk of obstructive sleep apnea. B12 deficiency can potentially cause thyroid issues in some people. One study found patients with sleep apnea had significantly lower B12 levels compared to those without the condition. Researchers think low thyroid hormone levels may relax throat muscles increasing airway collapse during sleep. Treating the B12 deficiency may help lower sleep apnea severity.
What are the symptoms of B12 deficiency?
In the early stages of deficiency, symptoms may be very subtle. Some of the first signs can include:
- Weakness and fatigue
- Lightheadedness or dizziness
- Heart palpitations
- Shortness of breath
- Sore tongue
- Nausea
- Loss of appetite
- Weight loss
- Constipation and diarrhea
Neurological symptoms may start to appear as B12 levels drop more significantly over time:
- Numbness or tingling in the extremities
- Difficulty walking or moving
- Vision loss
- Depression, severe mood swings and behavior changes
- Memory loss
- Disorientation and confusion
- Paranoia
- Hallucinations
- Cognitive decline and dementia
Symptoms related to sleep may include:
- Excessive daytime sleepiness
- Insomnia
- Frequent nighttime awakenings
- Restless leg syndrome
- Difficulty staying asleep
How is B12 deficiency diagnosed?
Doctors can check for B12 deficiency through a simple blood test. Two measurements are:
Serum B12 Level
This directly measures the amount of circulating vitamin B12. Levels below 200 pg/mL indicate a vitamin B12 deficiency. Borderline deficiency is between 200-350 pg/mL. Normal levels are 500-600 pg/mL.
Methylmalonic acid (MMA)
MMA levels increase when B12 levels are insufficient. An MMA blood test above 0.4 micromol/L indicates deficient B12 status. Checking MMA gives a more accurate view of tissue levels of B12 and is used to confirm if borderline B12 levels are truly deficient.
Doctors may also check blood counts since B12 deficiency causes certain patterns. High or high normal levels of MCV and low counts of lymphocytes or neutrophils can indicate low B12.
How is B12 deficiency treated?
Treating B12 deficiency involves supplementing with B12 to restore normal levels in the body. This is most commonly done through:
B12 Injections
B12 shots or injections are frequently used, especially if deficiency is severe. Injected B12 gets absorbed directly into the bloodstream, allowing for fast improvement of levels.
Typical protocols are 6 shots over 2 weeks, then a maintenance shot every 1-3 months. Some protocols inject 1000-2000 mcg per dose. People with pernicious anemia or absorption issues likely need lifelong maintenance shots.
High Dose Oral Supplements
For milder cases, high dose B12 supplements taken orally can help improve levels. Supplements range from 500 mcg to 1000 mcg per day. Sublingual tablets or sprays that absorb under the tongue are better than standard pills.
It takes longer to restore B12 levels with oral doses compared to injections. But supplements are easier to manage long-term. Those with mild malabsorption may need 1000-2000 mcg daily.
Dietary Changes
If deficiency is due to being vegan or vegetarian, eating B12 rich foods like eggs, dairy, seafood or fortified foods can help. Otherwise, food may not raise blood levels high or fast enough to correct a deficiency compared to supplements.
Along with B12 treatment, iron supplements may help if anemia is present. Getting good sleep, reducing stress, eating well and exercising also supports recovery.
What is the link between B12 levels and sleep?
Research indicates there may be some correlation between vitamin B12 and sleep quality:
Studies on B12 Deficiency and Sleep
Some studies have found connections between low B12 and sleep disturbances:
- A study of 62 patients found that treatment of B12 deficiency improved scores on sleep dysfunction assessments over 6 months.
- Another small study saw B12 injections appeared to alleviate sleep issues for all 8 participants.
- Research on East Indian vegetarians found vitamin B12 deficiency was more common in those reporting insomnia and sleep disturbances.
- Studies show older adults with sleep-wake cycle disturbances are more likely to have low B12 levels.
Although research is limited, these studies suggest there could be a link between restoring B12 levels and improving sleep quality in some cases.
Possible Mechanisms
Here are some of the ways B12 deficiency may impact sleep:
- Anemia – low oxygen from too few red blood cells can impair sleep.
- Neurologic effects – issues like pain, tingling, Alzheimer’s and dementia can interfere with sleep.
- Methylation issues – B12 helps make melatonin and serotonin which control sleep/wake cycles.
- Hormonal effects – Low thyroid function from B12 deficiency may increase risk of sleep apnea.
More research is still needed to understand the exact mechanisms involved. But addressing anemia and neurologic symptoms may help resolve associated sleep disorders.
Other factors that affect sleep
While low levels of B12 could potentially impact sleep, many other factors influence sleep quality including:
Sleep Environment
External factors like noise, light, temperature and furniture can disrupt sleep. Making the sleep area darker, cooler, and quieter promotes better rest.
Sleep Hygiene
Habits around sleep timing, napping, food and activity improve or hinder sleep. Having a consistent pre-bedtime routine of relaxing habits helps prepare the body for restful sleep.
Mental Health
Anxiety, depression, stress and worry frequently cause insomnia. Managing mental health through counseling, meditation, medication or lifestyle changes may relieve sleep issues.
Physical Health
Chronic pain, incontinence, breathing issues, digestive problems, hormonal changes and other illnesses can impair sleep quality. Treating underlying medical conditions often helps sleep.
Medications
Many common medicines like cold & allergy pills, steroids, stimulants and certain antidepressants interfere with sleep as side effects. Adjusting medication timing can prevent sleep disruptions.
Tips for improving low B12 levels
If a B12 deficiency is suspected or confirmed through testing, here are some tips that can help restore levels:
Get tested annually
Many doctors don’t routinely check B12 levels. Consider getting tested during annual physicals, especially if over 50 or have absorption issues.
Take B12 supplements
Correcting deficiency requires B12 supplementation, either through shots or high-dose oral supplements. Work with a doctor to determine the right treatment protocol.
Treat causes
Manage any underlying digestive or absorption issues. Consider a gluten-free diet for improved absorption if celiac disease is present.
Eat B12 foods
Add B12-rich animal products like fish, eggs, dairy and fortified cereals. B12-fortified nutritional yeast can be used as well.
Improve sleep hygiene
Getting regular exercise, cutting back on stimulants, limiting electronics before bed, and having a nightly routine supports healthy sleep whether B12 deficient or not.
Reduce stress
Chronic stress and anxiety strains the body, disturb sleep and deplete B12 stores. Relaxation practices like yoga, meditation and mindfulness help lower stress.
Conclusion
In summary, there is some evidence low B12 levels may contribute to sleep disruption for certain people. The exact mechanisms linking B12 and sleep are still being researched. Treating an underlying B12 deficiency through diet, supplements or injections may help alleviate associated restless sleep, insomnia and daytime fatigue. However, many factors influence sleep quality. Optimizing sleep hygiene, reducing stress, and treating other health conditions can improve sleep regardless of B12 status.
Testing B12 levels yearly and keeping them in the optimal range through supplementation ensures this essential nutrient is not overlooked. Pay attention to possible deficiency symptoms like unusual fatigue, weakness or neurological issues. Discuss any sleep problems thoroughly with your doctor to identify root causes and appropriate treatment options. Catching and correcting a B12 deficiency early can help minimize its effects on sleep and long-term health.