Dear Dr. Toshi,
"Sometimes people say their spouse is crabby so they should have their vitamin B12 level checked. Can a low B12 level really make somebody crabby?"
My answer is, "It's possible." If someone is anemic due to a vitamin B12 deficiency, they can experience symptoms like fatigue, irritability, and cognitive decline. Even people with a low B12 level who aren't anemic can have other symptoms of that deficiency, including irritability. Vitamin B12 deficiency can cause a number of symptoms such as glossitis (pain, swelling, and tenderness of the tongue), numbness and/or tingling in the legs (usually more than in the arms), difficulty walking, and weakness that continues to get worse over time. Other symptoms may include neurological or psychiatric problems like depression or mood changes, insomnia, forgetfulness, vision changes, and restless leg syndrome. But vitamin B12 deficiency isn't the only cause of mood changes, of course.
B12 is a very important vitamin that we need for making red blood cells, healthy nerves, and the DNA in our cells. A vitamin B12 deficiency can cause anemia and neuropsychiatric issues. Our bodies don't make this vitamin, so we have to get it from food or supplements. It's in animal products such as meat, dairy, and eggs, and the highest concentrations are found in clams and liver. (But clams and liver are high in cholesterol, so don't eat too much of them!) Many breakfast cereals are also fortified with vitamin B12.
Plants don't contain any vitamin B12, so if you're a strict vegetarian or vegan, you need to take a vitamin B12 supplement. It's recommended that adults take 2.4 micrograms (mcg) per day, but the recommended amount for children depends on their age.
In food, vitamin B12 is bound to protein, so when we eat it, it gets separated from the protein in the stomach and absorbed in the small intestine. However, if you have acid reflux or heartburn and take an over-the-counter proton pump inhibitor medication such as Prilosec (omeprazole) or Nexium (esomeprazole), or an antacid medicine like TUMS, Pepto Bismol, Maalox, Rolaids, etc., or an H2 blocker such as Pepcid (famotidine) or Tagamet (cimetidine), then you are at risk of developing a B12 deficiency because all those medications change the environment of your stomach, interfering with vitamin B12 absorption because the acid in your stomach separates the B12 from the proteins in food. It's good to be aware that there are other medications that also interfere with B12 absorption, but I won't get into those today.
Our body stores vitamin B12 quite well, and on average we store a total of about 2 to 5 milligrams (mg), with half of it stored in the liver. So, it could take quite a while to develop a vitamin B12 deficiency if you're healthy and have been eating a regular diet.But if you develop symptoms, you should be seen by your primary care provider.
If you take a lot of medication for acid reflux, or if you're a vegan or follow a strict vegetarian diet, drink too much alcohol, have gastrointestinal problems, have had surgery in your gastrointestinal system such as bariatric surgery, or have an ulcer or gastritis (inflammation in the stomach), or if you're experiencing other concerning symptoms, please talk with your primary care provider about this.
Dr. Toshiko ("Toshi") Luckow, MD, is a Family Physician at the West River Health Services Hospital and Clinics.