Consider getting yourself tested for B12 deficiency (it is a blood test). My doctor decided to check my levels, even though I have no symptoms, and I am surprised that it is really low (157 compared to functional level of 400+… and by functional, I mean the lab says the bottom of the range is 212, but you may have symptoms below 400).
Symptoms can include: fatigue, GI issues (diarrhea/constipation), tingling/numbness in fingers/toes, migraines, dizziness, anxiety, irritability, depression, forgetfulness, sore mouth/tongue, weakness, difficulty with balance / abnormal gait, chest pain, difficulty breathing, insomnia.
B12 is necessary to maintain the myelin sheath around your nerves, so the longer it is deficient, the more likely you are to have nerve damage and the symptoms that go along with it. Because of this, B12 deficiency can look like MS, Parkinson’s and other conditions that impact motor skills, as well as Alzheimer’s and other conditions that impact cognitive function. (Note: you may not have any symptoms and can still be deficient.)
Risk factors for B12 deficiency: vegetarian (or mostly, like myself… even if you don’t eat a lot of red meat or shellfish, you still could be), pregnancy, low stomach acid (which can be caused by hypothyroidism, being 50+ years old, using PPIs, among other things), food allergies, pernicious anemia / celiac disease / other autoimmune diseases, intestinal parasites, use of proton pump inhibitors / birth control pills / metformin, or pancreatic insufficiency (your pancreas doesn’t make enough digestive enzymes to release B12 from the animal products you eat)
If you are really deficient, your doctor will likely recommend B12 injections. You can also take a supplement. However, cyanocobalamin is the form of vitamin B12 that is in most supplements and it is not well absorbed in the body. Pick a supplement with at least 1000 micrograms (mcg) of methylcobalamin, the form of B12 that is easily absorbed through the intestine. Or increase your intake of animal products that are rich in it: sardines, salmon, lamb, scallops, shrimp, beef, and yogurt.
NOTE: Anemia is NOT an indicator of B12 deficiency. Anemia used to be associated with a B12 deficiency due to its involvement with folate, but now that our food is folic acid fortified, B12 deficiency doesn’t show up as anemia. In fact, my B12 has never been checked because all of my blood markers for anemia are always fine. My MD decided to check it on a whim!