Injections are commonly used for individuals suffering from an inability to digest and absorb B12. Cyanocobalamin was created years ago in a lab using cyanide as a means for stabilization, and many low-quality supplements include this form.

B-12 Side Effectsī-12 occurs naturally in three forms: methylcobalamin, adenosylcobalamin, and hydroxocobalamin. An inability to digest B12 as a result of low levels of intrinsic factor – for either genetic reasons or a result of physical damage to the stomach or small intestine – can also cause deficiency.Ĭommon symptoms include numbness in the hands and feet, moodiness, memory concerns, dementia, poor red blood cell formation, impaired DNA function, and fatigue. Inadequate dietary consumption of foods containing B12 such as red meat, fish, or dairy products – an issue for many vegetarians and vegans – can lead to deficiency. Symptoms of Deficiencyĭeficiency can result for a couple of reasons. Even sublingual absorption (absorption through tissues of the mouth) doesn’t reach levels which would be of cause for concern. Oral ingestion of large amounts of B12 is highly unlikely to cause an issue, as not all B12 survives this process. The amount of B12 that does get absorbed is directly related to the amount of intrinsic factor available.

To survive the digestive process, B12 must connect with intrinsic factor before it can enter the system. High doses of vitamin B12 have a low absorption rate when taken orally. Let’s quickly give a brief overview of how vitamin B12 is absorbed. Does vitamin B12 have any side effects? Here’s what you need to know.

Generally, the worst side effects for vitamins – including B vitamins – are diarrhea, nausea, rashes, and vomiting. Experiencing unpleasant side effects of a supplement is by no means enjoyable, and it’s best for consumers to do their research before diving into any supplement approach. Vitamin C, for example, may promote loosening of the bowels if taken in excess, and too much niacin (B3) may cause a disagreeable flushing. Side effects are possible for any food, supplement, or medication, and everyone reacts differently to different products.

Vitamin b12 side effects