This vitamin is needed in order to have healthy red blood cells and a healthy nervous system. Other benefits of B12 include alleviating depression in the elderly, improving life for asthma sufferers, assisting us with our sleep (due to its role in melatonin production). reducing the ringing in the ears of people with tinnitus and increasing the sperm count in men whose counts are low.
When B12 is ingested, it is released into your body by the action of hydrochloric acid and enzymes. As it reaches your stomach lining it is bound with a secretion called Intrinsic Factor (IF) and then moved along to your small intestine. If the small intestine is working properly the B12-IF is passed through the walls into the bloodstream.
Once absorbed, the B12 is stored in the liver until needed, for up to three years. Any excess is secreted in the urine.
Your body gets Vitamin B12 from animal foods, mainly meat and fish. It is not naturally available from plant foods, so if you are a gluten free vegan you need to ensure your levels are not too low.
Good sources, for those NOT on a vegan diet, include...
Shellfish is particularly good as the molluscs syphon the ocean floor and pick up micro-organisms that produce B12.
Eggs contain vitamin b12, but they also contain a substance that can block its absorption into the body. An overconsumption of soy foods and spirulina, can also either block the B12 intake, or increase the body's need for it.
The following signs can all suggest that it would be wise to get your B12 levels checked.
If you are a diagnosed celiac your doctor should test for a deficiency as a matter of course. It can, however, depend on where you live, as to whether your results are considered low. In the USA a level less than 200 pg/ml is considered low, whereas in Europe and Japan anything lower than 500-550 signals danger!
Normal levels are considered to be between 500 and 1300.
If your levels are low it is important to rectify the problem, as a B12 deficiency can lead to pernicious anaemia (also due to a deficiency of Intrinsic Factor), osteoporosis (bone loss) and a weakened immune system.
These are normally prescribed by your doctor. They have the benefit of increasing the levels very quickly, important if you have just been diagnosed. You would normally have a series of injections, starting daily, then weekly (for the first month), then on a continual monthly or quarterly basis.
They do tend to sting, perhaps due to the preservatives in the shots. The price can sting a bit too!
There are other options to the shots. You may prefer the sublingual tablets that dissolve under your tongue, or B12 patches. You can purchase these in health food shops or online.
The recommended dose tends to be 100-250 micrograms per day but for those of us with absorption problems that can go up to 1000-2000 micrograms per day. Check with your doctor if you are unsure what dose you need.