Know your vitamins? A lesson in B12
How well do you know your vitamins and minerals? Why do you need Vitamin A, C, D, or even K? What do thiamine, riboflavin, niacin and folic acid have in common? What does zinc or iron do for you?
While I’m a bit of a health nut, I’m occasionally reminded of my virtual vitamin illiteracy.
Vitamin pop quiz
Vitamins are essential nutrients found in foods.
The two different types of vitamins are fat-soluble vitamins (vitamins A, D, E and K) and water-soluble vitamins (all the B-vitamins and vitamin C).
Fat-soluble vitamins dissolve in fat before they are absorbed in the blood and excess is stored in the liver. Water-soluble vitamins dissolve in water and are not stored by the body, so we need a continuous daily supply in our diet.
See if you can match the function and foods to the water soluble vitamin.
1. Which vitamin is an antioxidant that is needed for healthy skin and immune function and is found highest in red bell peppers, citrus, kiwi and strawberries?
2. Which vitamin helps the body metabolize carbohydrates and is highest in pork, fish and beans?
3. Which vitamin helps convert food to energy and make red blood cells and is highest in almonds, eggs and fish?
4. Which vitamin helps support enzymes and production of cholesterol and is highest in tuna, meat and beans?
5. Which vitamin helps regulate stress hormones and is found in avocados, dairy and mushrooms?
6. Which vitamin helps in cognitive and immune function and is found in chickpeas, liver and fish?
7. Which vitamin often helps with hair, skin, and nail growth and is found in egg yolk, liver, and salmon?
8. Which vitamin is needed in pregnant women to prevent birth defects and is highest in beans and dark leafy greens?
9. Which vitamin needs stomach acid to be absorbed and can be found in shellfish, fish, meat, dairy and nutritional yeast?
1. Vitamin C.
2. Vitamin B1 or thiamin.
3. Vitamin B2 or riboflavin.
4. Vitamin B3 or niacin.
5. Vitamin B5 or pantothenic acid.
6. Vitamin B6 or pyroxidine.
7. Vitamin B7 or biotin.
8. Vitamin B9 or folate.
9. Vitamin B12 or cobalamin
SOURCE: Nina Crowley, registered dietitian, MUSC Bariatric Surgery Team
I chalk it up to not being a believer in taking supplements and I also feel that eating whole, mostly fresh foods and my love of sunshine (Vitamin D) will take care of my body’s vitamin and mineral needs.
Of course, some people need to supplement. Vitamin and mineral deficiencies can cause serious health problems. But until a doctor or dietitian tells me I have to supplement, I won’t.
My latest reminder of my lacking knowledge of vitamins came via a comment on Facebook by a wise, “senior” running friend of mine, Irving Rosenfeld, in a discussion about protein needs for vegans.
Last January, I decided to go from my 98 percent vegetarian, or flexitarian, eating habit to a full-on vegan diet. Like me, Rosenfeld doesn’t buy the argument that the only way to get sufficient protein, or essential amino acids, is by eating meat, dairy and eggs. There are plenty of sources of protein in plants if you know what you’re eating.
But Rosenfeld did give, according to some of my vegetarian and vegan friends, the more sophisticated argument about vegans needing to supplement the B12 vitamin.
B12, it turns out, is one complicated yet critical vitamin.
I did a quick search and found out that B12, found in many meat and dairy products, is important in metabolism, the formation of red blood cells, and in the maintenance of the central nervous system.
Deficiencies are characterized by anemia, fatigue and weakness, numbness and tingling in the hands, poor memory, difficulty maintaining balance and depression.
But alas, there was no need to panic in the near term.
Nina Crowley, a registered dietitian at the Medical University of South Carolina, says B12 can be stored in the liver for three to 10 years.
“We typically store 2 to 5 milligrams and only excrete a fraction each day,” says Crowley. “But if body stores are not replenished from eating foods with B12 or taking a supplement, we can become deficient.”
Besides some vegans, Crowley says deficiencies typically are found in those with digestive issues and specifically those lacking the gastric “intrinsic factor” protein, such as older adults, people with pernicious anemia, celiac and Crohn’s disease, those who take medications to reduce stomach acid and those who have undergone bariatric surgery.
“After eating B12-containing food, stomach acid helps break the B12 away from the protein. Then intrinsic factor combines with the B12 and gets into the cells of the body. Once the body uses vitamin B12, leftover amounts leave the body through the urine,” says Crowley.
I posed the B12 question on the Charleston Veggies and Vegans Facebook page and got an array of responses on B12.
Some took supplements. Others ate fortified food or added a horrendous-sounding “nutritional yeast” to their food. (The yeast actually has a satisfying nutty, cheesy taste.) Some even had a blood test to measure their B12 levels. The results, again, were mixed. Some were normal; others deficient.
Danielle Dibetitto, the healthy eating educator at Whole Foods Market in Mount Pleasant, often fields questions about vegans and B12.
She recommends that vegans eat foods, such as nutritional yeast, fortified nondairy beverages such as soy and almond “milk,” and cereals before going to supplementation.
“Most people, and most vegans and vegetarians, are not deficient in B12. It’s very easy to figure out if you are with a blood test. If people feel fatigued or believe their health is being compromised by a lack of B12, it may be worth a blood test.”
A blood test?
Crowley agrees, saying that low serum/plasma vitamin B12 levels, elevated serum homocysteine, or elevated methylmalonic acid would confirm diagnosis.
At MUSC, a test would cost $194 before submitting it to insurance companies for possible coverage.
“Supplementation would be based on severity of deficiency but include tablet, lozenge, sublingual, nasal spray, or intramuscular shots/injections,” says Crowley.
Local chef and vegetarian Ken Immer says the B12 argument is “yet another red herring against choosing a plant-based diet.”
“There is not some sort of pandemic of B12-deficient people ... just as there is almost no one in America with a protein deficiency,” says Immer.
Reach David Quick at 937-5516 or dquick@postand courier.com.