One of the main functions of vitamin B12 occurs in our blood stream. B12, along with folate and iron, helps to form healthy red blood cells. This is needed for effective oxygen transport to each and every cell in our body. This efficient supply of oxygen to our cells is fundamental to our health.

B12 is also involved in the maze of metabolic pathways inside our body. They all operate to breakdown the food we eat into its simplest form; proteins to amino acids, carbohydrates to glucose and fructose, and fats to fatty acids. These simple forms can then be reformed to satisfy the specific needs of our body. Think of it like ingredients in our pantry. If we have flour, sugar, butter and eggs, we can make an array of things as we need to. Our body likes to break everything down to their base elements and construct them from the ground up. B12, along with other B vitamins and minerals, are all involved in this process.

B12 is also needed by our brain and nervous system. It helps with the signaling of messages from one part of our body to another. This is essential for the synchronized function and proper communication inside our body.

Before B12 can take part in all these duties, it needs to be efficiently absorbed by our body. B12 absorption happens in our stomach and relies on something called an intrinsic factor. It’s essential for B12 absorption and it’s produced by certain cells in our stomach. Healthy individuals naturally produce this intrinsic factor, so providing we consume enough dietary B12, our body can do the rest.

Vitamin B12 can be stored in our body in potentially high amounts. So even if our diet is lacking in B12, the symptoms may not show up for years to come. However, this can be dangerous. We may not be aware of a B12 deficiency until our stores are nearly depleted.

A B12 deficiency can result for a few reasons. The first is an autoimmune disease called Pernicious anemia. This impairs the secretion of intrinsic factor into our stomach. B12 needs the intrinsic factor to be absorbed into our body. Regardless of our dietary intake of B12, if we fail to secrete this intrinsic factor, the B12 goes unabsorbed and our body goes without. It’s like trying to fill a sink with water, but not having a plug to catch it; the water goes down the drain instead of collecting in the bowl.

Another cause is a lack of digestive juices in our stomach. All nutrients are bound in food until our body digests it and unleashes the goodness. B12 requires the presence of stomach acids to unlock it. Without adequate stomach acids, the B12 can’t get out and our body can’t absorb it, even if the intrinsic factor is there. Stomach ulcers and abuse of medications, both prescription and over the counter, can all interfere with the proper production of stomach acid. This can result in limited digestion that hinders the release and absorption of vitamin B12.

Vegans also run the risk of a B12 deficiency. B12 is found only in animal products, so a strict vegan diet for many years with no supplements or B12 fortified foods, can lead to a dietary B12 deficiency.

A B12 deficiency, either from a lack of intrinsic factor, poor dietary intake or digestion problems, can also cause megaloblastic anemia. This can result from a B12 and/or folate deficiency. Megaloblastic anemia is defined as enlarged and inefficient red blood cells. When our red blood cells are forming, they need the essential nutrients to grow, divide and produce more healthy red blood cells. Two of these nutrients are vitamin B12 and folate. In a shortage, our red blood cells start to grow but fail to divide, leaving enlarged and malfunctioning red blood cells. These large and malformed red blood cells are incapable of efficiently transporting oxygen around our body. This is megaloblastic anemia.

Both Megaloblastic and Pernicious anemia have similar symptoms to iron deficiency anemia. They include fatigue and low blood pressure, as well as nervous system problems like cognitive and memory troubles, and tingling or numbness in the arms and legs.