B12 / Deficiency, Risk Factors, Symptoms
There’s no question that vitamin B12 is essential for health.
This nutrient is responsible for numerous functions in your body, including red blood cell formation, energy production, DNA formation and nerve maintenance, protein synthesis.
Humans get vitamin B-12 just from animal products; both meat and dairy products are dietary sources of vitamin B-12. Our bodies store a greater amount of vitamin B12 than that of any other vitamin: between 2000-4000 µg, the majority of which is found in the liver. Theoretically, the body could function on a minimum provision of 1 µg per day for up to 10 years. This is one reason why the serious effects of vitamin B12 deficiency (such as pernicious anemia, mental problems…etc.) can take several years to emerge.
Some argue that the body stores B12 to ensure that irregular intake does not have a negative impact on health, indicating just how important it is for us. It could also be due to the fact that meat was less common in the diets of our ancestors.
The Structure of the Body’s Vitamin B12 Storage System:
There are three natural forms of vitamin B12 found in the body: adenosyl cobalamin, methyl cobalamin and hydroxocobalamin. The following values are the average B12 levels found in the body’s reserves :
- Liver: 2000 µg of adenosyl cobalamin
- Cell plasma (total): 35 µg of methyl cobalamin and 430 µg of hydroxocobalamin.
Every day around 0.1% of our bodily B12 reserve is lost via the urine, regardless of how much is stored. This means that the higher the level of the reserves, the higher the amount of B12 excreted
Physiological amounts of vitamin B12 (cyanocobalamin) are absorbed by the intrinsic factor mediated mechanism exclusively in the ileum. Human feces contain appreciable quantities of vitamin B12 or vitamin B12-like material presumably produced by bacteria in the colon, but this is unavailable to the non-coprophagic individual.
Vitamin B12 Deficiency and Diseases:
Today, high-dose vitamin B12 is used in the treatment of various diseases. These include in particular:
- Anemia
(pernicious anemia) - Mental illnesses
(depression, psychosis, schizophrenia etc.) - Neurological diseases
(neuropathies, nerve disorders, dementia etc.) - Chronic systemic diseases
(chronic fatigue, fibromyalgia etc.)
Especially in the field of mental and neurological diseases, very good results can be achieved with high doses of vitamin B12.
B12 concentration:
Vitamin B12 status is typically assessed via serum or plasma vitamin B12 levels. Values below approximately 170–250 pg./mL (120–180 picomole/L) for adults indicate a vitamin B12 deficiency. However, evidence suggests that serum vitamin B12 concentrations might not accurately reflect intracellular concentrations. An elevated serum homocysteine level (values >13 micromole/L) might also suggest a vitamin B12 deficiency. However, this indicator has poor specificity because it is influenced by other factors, such as low vitamin B6 or folate levels . Elevated methylmalonic acid levels (values >0.4 micromole/L) might be a more reliable indicator of vitamin B12 status because they indicate a metabolic change that is highly specific to vitamin B12 deficiency.Although not clinically validated or available for widespread use, measurement of holotranscobalamin, the metabolically active form of vitamin B12, is an emerging method of detecting deficiency.
Who is at risk for vitamin B12 deficiency ?
Risk factors for vitamin B12 deficiency anemia include:
- A family history of the disease
- Having part or all of your stomach or intestine removed
- 3Autoimmune diseases, including type 1 diabetes
- Crohn’s disease
- HIV
- Some medicines: metformin, chloramphenicol (Chloromycetin) which is an antibiotic , H2 receptor antagonists (ranitidine), proton pump inhibitors (omeprazole).
- Strict vegetarian diets
- Being an older adult
- Hashimoto’s thyroiditis
- Graves’ disease
- vitiligo
Vitamin B-12 deficiency affects the nervous system, leading to a variety of symptoms.
Sometimes, these may be apparent before symptoms related to the anemia. Neurological symptoms vary and may be nonspecific (meaning that these are symptoms that can be caused by a number of different conditions). Feelings of numbness, tingling, weakness, Irritability, lack of coordination (Trouble walking), spasticity, paraplegia, smooth and tender tongue, glossitis and mouth ulcers, and fecal (diarrhea) and urinary incontinence. clumsiness, impaired memory, mood and personality changes can all occur, on very rare occasions, one symptom of B12 deficiency may be a high temperature. Both sides of the body are usually affected, and the legs are typically more affected than the arms.
A B vitamin complex supplement is often touted to boost energy levels and mood. People who have a B vitamin deficiency may feel a rise in energy levels after using the supplement because the vitamin is directly involved in making healthy blood cells and can correct anemia if present. However, there is no evidence of benefit if people without a deficiency take extra B vitamins.
What vitamin B12 can’t do:
The Internet is full of articles lauding the use of vitamin B12 to prevent Alzheimer’s disease, heart disease, and other chronic conditions or reverse infertility, fatigue, eczema, and a long list of other health problems. Most are based on poor or faulty evidence.
Take Alzheimer’s disease as an example. Although there is a relationship between low vitamin B12 levels and cognitive decline, clinical studies—including those involving people with Alzheimer’s disease—have not shown improvement in cognitive function, even doses of the vitamin as high as 1000 micrograms.
For now, it’s best to get enough vitamin B12 to prevent a deficiency, and not look to it as a remedy for what ails you.
Presented by: Pharmacist Ruba noueddin
References
- https://www.health.harvard.edu/blog/v…
- https://www.hsph.harvard.edu/nutritio…
- https://ods.od.nih.gov/factsheets/Vit…
- https://www.medicinenet.com/perniciou…
- https://www.hopkinsmedicine.org/healt… https://www.cedars-
- sinai.org/health-l… https://www.healthline.com/nutrition/…
- https://www.b12-vitamin.com/overdose/
- https://www.webmd.com/alzheimers/news…
- https://www.ncbi.nlm.nih.gov/pmc/arti…
- https://www.ncbi.nlm.nih.gov/pmc/arti…
- https://www.ncbi.nlm.nih.gov/pubmed/1…
- https://www.healthline.com/health/b12…
- https://veganhealth.org/intestinal-ba… https://healthfully.com/intrinsic-
- fac… https://www.b12-vitamin.com/body-store/
