B12 Supplement Side Effects: What are they?

B12 Supplement Side Effects

Vitamin B12 is a water soluble vitamin, excess amounts are excreted through the urine.  Some B12 is stored in the liver in small amounts, this is the amount that shows up when you have blood work done. Most of the time B12 serum levels test in the normal range and it takes years for a deficiency to  show up, by the time it is diagnosed, irreversible nerve damage has already occurred. B12 is considered non-toxic, therefore, B12 supplement side effects are rare.

Who Is At Risk

Although B12 is not toxic, there are a small amount of people that are allergic. Some of the symptoms of a B12 allergy are:

  • Numbness or tingling in the hands, arms and face
  • Nausea
  • Diarrhea
  • Rash
  • Difficulty swallowing

In very rare cases anaphylactic shock may occur.

There are a few medical conditions that have a negative interaction with B12 supplementation:

Leber’s Disease – this is a disease of the eye. Taking B12 if you have Leber’s Disease can damage your optic nerve.

Gout – B12 may trigger gout in those individuals susceptible.

Stents – B12 supplements can lead to a narrowing of the blood vessels.

Vitamin allergies are very rare. Most times if you have an allergic reaction to a supplement, it is not the vitamin  causing the problem, it is usually a different ingredient like fillers, dyes, etc.


Why Do We Need B12

Unless you are in the handful of folks in the categories mentioned above, you probably need to be taking a B12 supplement.  Here are a few of the reasons our bodies need B12:

  • Proper digestion, food absorption, iron use, carbohydrate and fat metabolism
  • Healthy nervous system function
  • Normal nerve growth and development
  • Cell formation & longevity
  • Healthy immune system function
  • Feelings of well-being and mood regulation
  • Mental clarity, concentration and memory
  • Physical, emotional and mental energy

As you can see from the list, B12 has a big job. You should not procrastinate any longer, don’t delay starting a supplement for the risk of overdose, toxicity or allergic reactions (unless you are in the small categories outlined above).

For most people it would be far better to take more than the RDA of B12 than to take too little.

Some facts about levels of B12:

  • 40 % of the population between the ages of 26-83 have a low-normal level of B12.
  • 40% of the population over 60 have a B12 deficiency.
  • Most of the symptoms related to aging  such as – Memory loss, cognitive decline, decreased mobility – can all be due to a Vitamin B12 deficiency.
  • People that are diabetic and take Metformin are probably B12 deficient.
  • People that have taken Prilosec, Prevacid, Nexium, Pepcid, Zantec, or Tagamet for long periods of time are probably B12 deficient.
  • 50% of long-term vegetarians have a B12 deficiency.
  • 80% of Vegans are B12 deficient.

Effects of Vitamin B12 Deficiency

  • Mental fogginess
  • Memory problems
  • Mood swings
  • Lack of motivation
  • Feelings of apathy
  • Fatigue/lack of energy
  • Muscle weakness
  • Tingling in your extremities
  • Depression
  • Dementia
  • Alzheimer’s
  • Insomnia

To do a self-assessment of your vitamin levels please visit the assessment section of my website.

 Cyanocobalamin and Methylcobalamin

There are several kinds of B12 but the two that most people are familiar with are Cyanocobalamin and Methylcobalamin.

Most doctor’s offices and clinics use Cyanocobalamin for their patients. Cyanocobalamin costs less, is more stable and has a longer shelf life. The problem is  – Cyanocobalamin is not really effective if you have a B12 deficiency. Cyanocobalamin must be converted to Methylcobalamin by your body before it can be used, it loses a lot of of its potency during the conversion.

If you have Chrohn’s Disease, smoke or consume alcohol you do not absorb B12 well and Cyanocobalamin would be ineffective.

If you take any kind of antacid medication, the medication inhibits your B12 absorption and Cyanocobalamin would be ineffective.

The most effective form to take as a supplement is Methylcobalamin, it does not have to be converted therefore as soon as you take it, your body starts using it.

Supplements or Injections

Injections are probably the best method of receiving B12 but there are many people that hate shots!

Injections are usually more expensive that supplements unless you are getting an injection of B12 once a month.  An injection of B12 once a month is relatively inexpensive, but it is also ineffective, you need more.

I personally recommend a liquid methylcobalamin.  It is very easy to use, dissolves quickly and works fast.  Please click here for my recommendations and great pricing.

Be the first to comment

Leave a Reply

Your email address will not be published.