To “B,” or Not to “B”:

The validity of injectable vitamin B12.

In the wellness industry there is a growing trend of inject-able vitamins, in particular B12.  Clinics are springing up and offering shots of the “skinny” vitamin for around $30-40.   Clients are promised these shots will: “Increase energy,  melt fat and help lose weight.”

Is this accurate? Are B12 injections a short cut to increased energy and weight loss; or is this just a sales pitch?   I decided to evaluate the scientific evidence.  I wanted to discover if B12 injections are necessary for most people; If such injections were the most cost-effective and efficient way of obtaining B12.  And if there were any dangers of  such mega dose injections.

What does B12 Do?

Firstly,  let’s be clear, B12 is an essential vitamin. This is not disputed. B12 is involved in all kinds of processes necessary for health. It is required for the production of red blood cells; it helps the nervous system to run efficiently: It is critical to many metabolic functions, including breaking down carbohydrates, metabolizing fat, and releasing energy.  It also helps the body detoxify and repair at the cellular level via a process known as methylation.

Unsurprisingly, deficiencies in B12 are linked to many health issues, including neurological conditions, depression, dementia, and cerebrovascular disease. Perhaps the most widely recognized condition resulting from a deficiency in B12 is megaloblastic anemia; a blood disorder where not enough red blood cells are made by the body, and they are improperly formed.

Sometimes, individuals become anemic because they are unable to assimilate B12 efficiently. This is the result of an autoimmune condition, in which the individual lacks “intrinsic factor;” a protein produced in the stomach, and essential for absorbing B12.

This is known as pernicious anemia, since red blood cells are essential for transporting oxygen, a deficiency will result in tiredness, fatigue, and low energy.

Therefore,  in light of the essential role B12 plays in the body, one can understand the rationale behind claims that B12 injections can support weight loss and provide energy.  However,  this only applies if someone has a legitimate deficiency.  It is incorrect to assume that B12 injections will have the same effect on people with a deficiency versus someone with normal levels.  It’s kind of like saying a car needs petrol to run. This is true, but overfilling the tank will not get more miles….

Why might someone be deficient in B12 ?

One reason for a B12 deficiency is inadequate dietary intake. Since the richest sources are animal origin strict vegetarians and vegans are at greater risk.

Likewise, people with limited or poor quality diets are also prone to deficiency.
Alternatively, another reason for deficiency is not a result of diet lacking in B12 per se, but poor absorption of B12. The most common form being pernicious anemia.
Older adults may be more at risk of deficiency because of age-related atrophic gastritis; or low stomach acid. Stomach acid is necessary to absorb B12 from food.
People with medical condition such as gastric bypass, Crohn’s disease, intestinal parasites or certain cancers are also are more at risk of a B12 deficiency.
Finally, medications can affect the way B12 is absorbed (the most common being metformin used to treat diabetes, and proton-pump inhibitors; used as an ant-acid for severe heartburn)

How can we get B12 in our diet?

An omnivore with a healthy varied diet can easily reach the recommended daily intake. Highest sources are  liver, trout, canned salmon, clams, red meat  (surprisingly chicken is relatively low). A vegetarian following a sensible diet including eggs and milk , nutritional yeast, fortified cereals can also  achieve the necessary intake. Vegans have to take more care to included fortified plant milk, small amounts are also present in nori or tempeh. However, generally a supplement might be recommended as a safety net.

How to take supplemental B12.

Despite the claims from clinics that B12 shots are the way to go.  There is no clinical evidence to suggest that injections are superior to oral supplements. (They are just more expensive….)  I would suggest,  the only caveat is if the individual is unlikely to comply with taking pills regularly. For example, forgetting to take supplements  due to alcoholism or dementia.  In this case injections would be preferable.  Also,  if an individual was diagnosed with pernicious anemia  or a condition in which absorption was the cause of the deficiency, then B12 injections are a more suitable and convenient option.

Risks from B12 injections

In general, the injections are relatively safe. The body can tolerate high levels of B12 with no real adverse affects. However, in rare cases hypokalemia (low potassium) could occur, symptoms include muscle cramps, weakness and palpations. Infection could also occur at the injection site, although this is uncommon.
However, certain medications can interact with these mega doses of B12, changing the way the medication works, and potentially increasing the risk of more serious side effects.

How can you tell if you are deficient in B12?

The best way to check for deficiency is a combination of reported symptoms and blood tests.
Most blood tests often measure the total amount of B12 in the blood; This means both ‘active’ levels, which can be used by the body, and ‘inactive’, which are not utilized by the body, are combined. As a result, a false negative can occur in which people can be have a deficiency while the levels appear normal.
Conversely, symptoms of B12 deficiency can be easily mis-attributed to other causes, or the person may not even experience symptoms.
Because B12 is so essential to the production of red blood cells, and keeping the nervous system healthy, common physical symptoms often include: weakness and fatigue, dizziness, depression, forgetfulness, pins and needles, balance problems, blurred vision, glossitis (swollen tongue) and mouth ulcers.
Of course, the above symptoms can be due to causes other than B12 deficiency.
It is essential therefore if you fall into one of the risk groups described, and are experiencing symptoms to speak with your health practitioner. Supplementing may help, but how you supplement (pills, sublingual, drinks, or injections) really does not make a significant difference.

In summary

B12 is an essential vitamin, and crucial to maintaining good health. But does the evidence support the claim that injections B12 will result in weight loss and increased energy? For most people with normal levels of B12, the answer is No. Certainly, there are other substances that have been shown to increase energy and lead to weight loss in normal people. Most of these are illegal, and have undesirable side effects… Unfortunately, there is no solid clinical evidence that megadose injections of B12 will result in weight loss and significantly boost energy in people who are not deficient.
It would seem, as much as we would like it to be true, there is no quick fix for energy and weight loss.
A healthy diet and lifestyle on the other hand will work wonders!
If you would like more info contact Dr. Jenny

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