While excess Vitamin B12 is generally considered safe because your body excretes what it doesn't need, extremely high levels might signal underlying health issues like liver or kidney problems and, in some studies, have been linked to increased mortality risk, though direct harm from the vitamin itself is rare. Side effects from very high doses can include acne, headaches, dizziness, or heart issues, but usually resolve when intake stops, with the main concern being what the high level indicates, not the vitamin itself.
High B12 levels might cause you some unpleasant symptoms, but they won't cause permanent damage. But too much of a good thing — even an essential vitamin like B12 — might still cause issues and signal other health concerns.
Taking doses of vitamin B-12 might cause: Headache. Nausea. Diarrhea.
Long or prolonged intake of high doses of vitamin B12 can lead to numbness or tingling sensation which usually occurs in the right side of your body. The presence of a tingling sensation or numbness are one of the first signs of vitamin B12 overdose.
Stay Hydrated: Drink plenty of water to help your body eliminate excess Vitamin B12 through urine. Monitor Underlying Health Conditions: If elevated B12 is linked to liver or kidney problems, adhere closely to your doctor's prescribed treatment plan.
Serious allergic reaction
High B12 levels typically indicate kidney dysfunction rather than causing kidney damage directly. Research suggests B12 may actually protect kidneys from injury, particularly in high doses according to mouse studies. Elevated B12 serves as a biomarker for kidney problems but is not considered toxic to kidney tissue.
In fact, some studies have even suggested the opposite. For instance, one study noted that individuals who regularly took vitamin B12 supplements gained between 2.5 to 17 fewer pounds (1.2 to 7.7 kg) over a decade than those who didn't supplement.
Taking vitamin B12 daily is generally safe for most people, as it's water-soluble and excess is flushed out, but high doses can cause mild side effects like headaches, nausea, dizziness, or diarrhea in some individuals, while very high levels (especially from injections) might rarely link to other issues, so it's best to stick to recommended amounts unless treating a diagnosed deficiency.
In conclusion, our results show that lower vitamin B12 was associated with insomnia symptoms and sleepiness in specific groups of participants. However, further research with objective measurements of sleep is crucial to assess the relationship between sleep and vitamin B12.
The foods highest in Vitamin B12 are animal products, with clams and liver (beef, lamb) being exceptionally rich sources, often providing several hundred percent of the daily value in a single serving, alongside seafood like mussels, sardines, and salmon, dairy, eggs, and fortified cereals and nutritional yeast for vegans.
While Vitamin B12 is generally safe, potential disadvantages (side effects) can occur, especially with high doses or injections, including headaches, nausea, diarrhea, weakness, skin issues (rash, itching), and rarely, more serious heart or allergic reactions (like anaphylaxis), though toxicity from oral intake is rare as excess is usually excreted. Conversely, a deficiency can cause serious problems like irreversible nerve damage, memory loss, fatigue, infertility, and increased risk of certain cancers, making proper intake crucial.
Strengthens Hair Follicles to Promote Growth
This vitamin supports the production of keratin, the protein that makes up hair strands, helping them grow thicker and more resilient. When your body lacks B12, hair follicles may become weaker, leading to slower growth and thinning hair.
The worst symptoms of B12 deficiency involve severe neurological damage, including severe memory loss, confusion, dementia, psychosis, hallucinations, balance problems, trouble walking, and irreversible nerve damage (neuropathy), alongside serious mental health issues like severe depression or irritability, with physical signs including extreme fatigue, pale skin, and a sore, smooth tongue. These severe cognitive and neurological issues are the most concerning because they can become permanent if left untreated.
Vitamin B12 does a lot of important things for your body. It helps create your DNA and red blood cells, for example. Your body also needs B12 for the development of your central nervous system (your brain and spinal cord).
This study provides suggestive genetic evidence for the causal relationships between serum vitamin B12 concentrations and risk of anxiety and bipolar affective disorders. Specifically, genetically determined higher vitamin B12 is associated with a higher risk of anxiety and bipolar affective disorder.
For example, too much vitamin C can raise your risk of kidney stones, specifically calcium oxalate stones. Vitamins A, E, and K usually don't need to be taken as supplements if you have CKD. Most people get enough of these vitamins in their diet, even with CKD.
5 Symptoms That Indicate High Vitamin B12 Levels
People may experience frequent episodes of dizziness with no apparent cause. Headaches may be persistent and more intense than common tension headaches.
They need to know if you have any of these conditions:
Studies have documented a positive correlation between elevated levels of B12 and the incidence of lung, pancreatic, and liver cancers, as well as certain hematological neoplasms, particularly those related to the myeloid lineage.
If you don't have a vitamin B12 deficiency, most of the vitamin B12 you get through your injection will be absorbed and eliminated quickly through your urine. This accounts for the people in the research that found 98% of their injected vitamin B12 in their urine 48 hours after it was administered.
For example, vitamins B6 and B12 play a key role in energy metabolism. However, taking large doses of these vitamins can also cause fatigue and other symptoms such as headaches, diarrhea, and nausea. Other vitamins that have been linked to fatigue include vitamin C and iron.
Vitamin B12 Deficiency Has Nothing To Do With Weight Gain
There is very little evidence to suggest that vitamin B12 affects the process of gaining or losing weight, despite the numerous techniques involved. Most of the evidence supporting this claim comes from a few observational studies.