Vitamin B12 Lab Values

Hey everyone. Abby here with NURSING.com. Today, we’re going to discuss a lab value for vitamin B12. Let’s get started!

The body doesn’t synthesize vitamin B12. Therefore, it has to be obtained through the diet or supplementation most often found in animal products. Vitamin B12 is responsible, or an essential nutrient rather, for red blood cell, white blood cell, and platelet formation in the bone marrow. It’s also an integral part of DNA formation and brain and nerve cell development and function. So, if this lab is low, I’m kind of thinking you might see some interesting things if we’re talking about these types of cells, right? So, what are some clinical indications? Let’s take a look. If we’re evaluating the serum, vitamin B12 in the blood, this patient may approach with neuropsychiatric changes. So, that could be like numbness and tingling. That could even be, uh, some weakness or complete loss of sensation. It can also be used as a diagnostic tool for pernicious anemia. GI symptoms can also be an indication to take this lab.

Now, what do we know about pernicious anemia? It’s a lack of B12, right? Or rather, it’s a lack of intrinsic factor therefore, B12 is not being digested. So, in normal situations, the value is 180 to 914 picograms per milliliter. It’s collected in a serum separator tube. When the lab value for vitamin B12 is increased, it typically indicates supplementation or injection. It’s rare to have too much of it and it’s actually considered non-toxic, but there always can be too much of a good thing. Decrease is what we’re far more concerned with. That could be that someone has an adequate intake. This could be a vegan diet, or even a mother who isn’t intaking enough and is breastfeeding their child, uh, or it could be someone that just really needs some supplementation like someone with pernicious anemia, right? This can also be linked to poor absorption. Some medications can lead to poor absorption in the stomach, as well as pancreatitis. If someone has pancreatitis, it means that those enzymes aren’t being produced, therefore digestion suffers, therefore vitamin B12 absorption suffers. Small bowel diseases like inflammatory bowel diseases or celiac can also create a problem for absorption. Gastric abnormalities like we talked about if there’s pernicious anemia and no intrinsic factor, then that B12, vitamin B12 is not going to be digested and distributed in the system therefore, our bone marrow will have trouble producing our blood cell components like red blood cells, white blood cells and platelets. 

So, linchpins for this lesson, vitamin B12 is an essential nutrient for creation of all of these incredibly important cells and cell fragments. Its normal value is between 180 and 914 picograms per milliliter. And, if the value is vastly increased, it’s usually related to replacement either via injection, or supplementation. It is very hard to overdo it in your diet. If it’s decreased, that’s when we’re really concerned that there could be inadequate intake, medications that are harming absorption, or abnormalities in the GI system also, leading to less absorption of vitamin B12. You all did great on this lesson. This wraps it up now, go out and be your best self today and as always, happy. Nursing!

References:

• https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-vitamin-b12-and-folate-deficiency?search=vitamin%20b%2012%20lab%20test&source=search_result&selectedTitle=4~149&usage_type=default&display_rank=3
• https://www.uptodate.com/contents/causes-and-pathophysiology-of-vitamin-b12-and-folate-deficiencies?search=vitamin%20b%2012%20lab%20test&topicRef=7155&source=see_link#H51743496
• https://www.uptodate.com/contents/vitamin-b12-deficiency-and-folate-deficiency-the-basics?search=vitamin%20b%2012%20lab%20test&topicRef=7155&source=see_link
• https://ltd.aruplab.com/Tests/Pub/0099431