The Truth About Vitamin B12 Overdose

The signs of vitamin B12 overdose are relatively scarce, largely because it is so difficult to physically overdose on this vitamin. There are some symptoms associated with the B12 vitamin that can be a little difficult to spot if you don’t know what to look for; however these symptoms usually don’t crop up as a direct effect on how much you take but rather by other factors.

Vitamin B12 Overdose – Is it Possible?

Vitamin B12 is a water soluble vitamin. This means that the body only keeps in store that which it will use; all of the excess is flushed out with water in the form of urine. The human body cannot synthesize this vitamin on its own and only stores this nutrient for a short time, so it is important that you get plenty of it through your diet or in the form of supplements. Because B12 doesn’t stay in the body for very long, it is quite rare for a person to actually overdose. In theory, the most likely cause for B12 failing to be expelled from the body would be in one were to become dehydrated with very little or no water intake. Because dehydration causes the body to have less water to use when flushing out toxins, any water soluble vitamins found in extreme excess could make the kidneys have to work harder during filtration. In this case, the urine would be extremely bright in color and have a foul odor due to the high concentration of vitamin B12. Excess levels of vitamin B12 that cannot be flushed from the body are stored within the liver which could also start to trigger minor side effects.

Side Effects of Vitamin B12 Overdose

There are certain circumstances that could make a person more susceptible to high B12 levels. The symptoms that crop up are usually indirectly related to vitamin B12 overdose and therefore the side effects can vary from person to person. There have been known cases in which individuals have suffered from allergic reactions to vitamin B12 supplements. This used to be the result of additives in the vitamin supplement that would trigger an immune system response. This hardly ever occurs anymore but it could be possible to suffer a reaction to the actual vitamin itself, although this is extremely rare. Signs of an allergic reaction to vitamin B12 are similar to a typical allergic reaction, including a runny nose, difficulty breathing, swelling, a breakout of hives, nausea, coughing, sneezing, vomiting, and diarrhea.

Another reported side effect of vitamin B12 overdose occurs in the form of a skin reaction. A rash may develop which could be localized or spread all over the body. It typically shows up a red bumps that can be accompanied by generalized swelling although this doesn’t always happen with a B12 rash. The rash may appear in the form of hives, or raised circular or crescent-shaped welts on the skin that disappear and reappear all over the body. It might also show up as an eczema rash that is very itchy and can become sore if scratched. A rash like this will last longer than a hives rash.

In addition to allergy symptoms and skin irritation, diarrhea, heart palpitations, and anxiety are other possible side effects of vitamin B12 overdose.

Taking B12 Responsibly

In order to avoid the possible symptoms of B12 toxicity, it helps to know how to responsibly maintain vitamin levels in your body. B12 is found in many foods that are probably already a part of your diet; but even if you decide to take a B12 vitamin supplement you shouldn’t have any worries about toxicity. There isn’t currently a guideline that states how much B12 is too much, largely because it isn’t clear how much of this vitamin it would take to become toxic. Levels of water soluble toxicity depends a lot on an individual’s personal metabolism, diet, and water consumption. The recommended dietary allowance for adults, each day, is between 2 to 3 mcg. Pregnant or nursing women should receive about 2.6 mcg of vitamin B12 as this vitamin is very important during fetal growth and throughout the first year of the child’s life; however there has been little research done to suggest the consequences of taking too much B12 during pregnancy or while nursing. The RDA for children under one year of age is between .4 and .5 mcg.

Foods that Contain Vitamin B12

You don’t have to rely on supplements in order to maintain good levels of B12. Several foods naturally contain this vitamin and other foods, such as certain breakfast cereals, are fortified with additional B12. The primary foods that contain B12 are meat products, including chicken, turkey, beef, pork, fish, and eggs. You can also obtain this vitamin by eating and drinking plenty of dairy products. You won’t get much B12 from non-fortified fruits and vegetables because this vitamin isn’t naturally found in these foods; however some organic products may have B12 added to them. The same occurs with breakfast cereal, in which the typical fortification level equals 100 percent of the RDA for adults.