High doses of vitamin B-12, such as those used to treat a deficiency, might cause: Headache. Nausea and vomiting. Diarrhea.
Healthcare professionals have not identified an upper limit blood level of vitamin B-12. The body will typically excrete excess vitamin B-12 that a person gets from the diet or via supplements. The body does not absorb vitamin B-12 supplements very effectively.
A high-dose B complex supplement (with 1,000 mcg of B-12) hurt, rather than helped, people with type 1 or type 2 diabetes and advanced kidney disease, resulting in a worsening of kidney function and an increase in the risk of heart attack, stroke and death.
Vitamin B12, or cobalamin, is naturally found in animal foods. It can also be added to foods or supplements. Vitamin B12 is needed to form red blood cells and DNA. It is also a key player in the function and development of brain and nerve cells.
Except for niacin (when given in high doses), there is no evidence that the other B vitamins, in physiologic or even super-physiologic high doses cause liver injury or jaundice.
Disturbed or blurred vision can also occur as a result of a Vitamin B12 deficiency. This happens when the deficiency causes damage to the optic nerve that leads to your eyes. The nervous signal that travels from the eye to the brain is disturbed due to this damage, leading to impaired vision.
Stores of vitamin B12 in the body can last around 2 to 5 years without being replenished, so it can take a long time for any problems to develop after a dietary change.
Increase Fluids
Since B vitamins are water-soluble, adding more fluid to your body helps remove them before they undergo absorption. Your health care provider may suggest consuming a large quantity of water in a short amount of time to flush excessive B vitamins out of your bloodstream.
Elevated cobalamin levels often accompany diseases such as leukemia, myeloproliferative disorders, hypereosinophilic syndrome, and metastatic cancer—especially when involving the liver.
Interactions between your drugs. No interactions were found between Vitamin B12 and Vitamin D3. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.
Internal Effects
Though this vitamin is naturally produced in your body, the injection of additional B12 may cause some internal side effects you should know about. It is common to experience headaches, dizziness, and weakness immediately after the injection. These should fade fairly quickly.
Research has suggested that the consumption of alcohol may reduce vitamin B12 levels. An older study indicated that moderate alcohol intake diminished vitamin B12 by 5% among “healthy, well-nourished, postmenopausal women.” Alcohol-related liver disease may falsely increase vitamin B12 test levels.
Low levels of B12 cause a reduction in the formation of red blood cells. The blood cells don't develop properly, and are unable to move into the bloodstream at the correct rate. This can lead to anaemia, a condition in which not enough oxygen is transported to the vital organs. This can lead to fatigue and weakness.
Vitamin B12 deficiency can have distressing neuropsychiatric symptoms. It can have an etiological role in clinical presentations like depression, anxiety, psychosis, dementia, and delirium, requiring screening of at-risk populations.
Deficiency of Vitamin B12 can result in hematological changes, neurological and psychiatric problems, which can manifest as irritability, changes in personality, depression, and memory loss [9]. It is also known to worsen depression by excitotoxic reactions caused by the accumulation of homocysteine [10].
Your iron and B12 status
Another common cause of dark under-eye circles is low iron and/or B12. This deficiency can result in poor oxygenation of bodily tissues and the effects of this are shown mostly under the eyes where pronounced, bluish veins are more visible.
Vitamin B12 is considered an important brain and nervous system micronutrient and is often used for anxiety. It helps to ensure normal function for your nerves, which can help combat physical symptoms of anxiety.
Macrocytosis associated with vitamin B12 deficiency is also associated with fatal and non-fatal coronary disease, myocardial infarction, stroke, and other circulatory health problems.
Vitamin B12 for Fatty Liver Disease
The researchers also found that supplementing with vitamin B12 and folic acid increased levels of syntaxin 17 in the liver, restoring its role of digesting fat and protecting against inflammation.
A lack of vitamin B12 can cause neurological problems, which affect your nervous system, such as: vision problems. memory loss. pins and needles.