Vitamin B12

Vitamin B12 is an essential vitamin that binds to the protein in foods we eat. It is needed to form red blood cells and DNA, and is a key player in the function and development of brain and nerve cells.

B12 Deficiency

Vitamin B12 deficiency occurs when the body does not have enough of the neutrient to perform its vital functions. Without sufficient B12, people can experience a host of issues. Understanding the relationship between B12 deficiency and brain health is vital in identifying and addressing this easily overlooked condition.

Risk factors for B12 deficiency include inadequate dietary intake (common in strict vegetarians and vegans), certain medical conditions (such as pernicious anemia, gastrointestinal disorders), and the use of specific medications that affect B12 absorption.

Diagnosis

Whilst you may be tempted to begin taking Vitamin B12 supplements when experiencing symptoms like brain fog, it's important not to self-medicate without a confirmed diagnosis. Supplementing without doctor guidance can mask a deficiency by showing a falsely elevated test value, complicating the diagnosis and delaying the discovery of underlying health issues.

Diagnosing Vitamin B12 deficiency begins with a B12 blood test as ordered by your doctor, however, while the blood test is a common starting point, it's important to note that having a B12 level within the 'normal' range does not rule out a deficiency. This is because the serum B12 test measures both active and inactive forms of B12, which can provide a misleading account of B12 available to the body.

To more accurately measure your B12, the below additional tests are recommended.

Holotranscobalamin (HoloTC)

Measures the amount of active B12 available for use by the body's cells. It's a more sensitive marker for early stages of B12 deficiency.

Homocysteine and Methylmalonic Acid (MMA)

Elevated levels of either can suggest a B12 deficiency, even when serum B12 levels are within the normal range.

If either of these additional tests are out of range, further testing for Intrinsic Factor & Parietal Cell antibodies should be carried out. The presence of these antibodies can indicate autoimmune conditions (e.g pernicious anemia) which affect B12 absorption.

Serum B12 values below 350 pmol/L (500 ng/L) fall into a grey zone. Despite typically being considered within "normal" range, these levels may suggest a functional B12 deficiency, particularly in individuals with symptoms such as brain fog, fatigue, or neuropathy.

Having one or more test values within the reference range doesn't mean you're not deficient, but having one value outside the range suggests deficiency.

Treatment

One a Vitamin B12 deficiency has been accurately diagnosed, treatment can begin. The treatment approach depends on the underlying cause of the deficiency, as well as the severity of the symptoms and test results.

Injections

For severe deficiencies or cases where absorption is hampered (e.g., due to gastrointestinal issues), Vitamin B12 injections are usually the first line of treatment. These injections bypass the digestive system and provide a direct, potent dose of B12. The frequency and duration of the treatment vary based on individual needs, ranging from daily to monthly injections.

Oral Supplementation

High-dose oral B12 supplements may be sufficient for individuals with milder deficiencies who do not have absorption issues. Oral supplementation can be effective, but it requires diligent adherence to the regimen to ensure B12 levels are restored.

Dietary Adjustments

Incorporating B12-rich foods into the diet for this treatment path is crucial. Foods such as meat, fish, eggs, dairy products, and fortified foods can help maintain adequate B12 levels, but your doctor should be your primary source of advice.

Nutritional Support

Folate: Ensure adequate folate intake of 1-5mg per day, either through diet or supplementation with bioavailable forms like methylfolate or folinic acid. High doses of B12 can induce folate deficiency symptoms, which requires careful management, especially in individuals with MTHFR mutations affecting folate processing.

Multivitamins: A high-quality multivitamin containing the full spectrum of B vitamins and trace minerals, including activated forms of these nutrients, is recommended. A product like Thorne's Basic Nutrients 2/Day is a solid choice.

Trace Minerals: Consider a separate trace mineral complex to support Riboflavin and B12 metabolism, focusing on Selenium, Iodine, and Molybdenum. Molybdenum, often absent in multivitamins, is crucial.

Vitamin D3: Given the connection between vitamin D deficiency and B vitamin dysfunction, supplementing of vitamin D3 may be beneficial. Monitor electrolyte levels, as vitamin D can deplete them.

Magnesium and Potassium: Adequate daily intake of magnesium (400-600 mg, avoiding oxide forms) is crucial. The same goes for potassium, which requires daily replenishment. The Recommended Daily Allowance for potassium should be followed, ideally obtained through a mixture of diet and supplements. Considering the risk of hyperkalemia, especially in those with renal issues, monitoring and moderation are key. An electrolyte drink mix might offer a balanced approach to maintaining electrolyte levels.

The goal of treatment is not only to normalize B12 levels but also to improve the overall quality of life by eliminating symptoms associated with the deficiency. Given the complexity of B12 metabolism and the variety of factors that can contribute to deficiency, a tailored treatment plan developed in consultation with healthcare professionals is essential.

It's commonly advised to persist with treatment until all symptoms have subsided, not merely until the B12 serum level surpasses 350 pmol/L (500 ng/L). Generally, measuring the serum B12 level during treatment is not meaningful as it becomes artificially elevated, potentially leading to misinterpretations, such as prematurely discontinuing treatment.