Tuesday, May 06, 2014

Vitamin B12 - What's the big deal?

First off, I am not an expert in nutrition. However, diet and health is an area of interest for me, especially when it comes to promoting a vegetarian or vegan lifestyle.  I have done some research on different topics over the years, mostly in relation to my own choices and health; but recently a student asked me to write about vitamin B12 and whether it is really a problem for someone taking up a vegan diet.  So, I thought this would be a good forum to discuss the issue at hand.

The main criticism of a vegan diet is that it cannot provide adequate nutrition.  The argument goes something like this: "Plant foods are completely lacking in vitamin B12, and obviously if we need a nutrient that we can't get from plants alone, then it is evident that humans are not meant to be strict vegetarians." 

So what's the deal with this vitamin B12?  Do we really need it and is it even important?

As it turns out, vitamin B12 is super important for our health at a fundamental level.  It is needed for cell division, blood formation and making DNA. 

The truth is that neither plants nor animals synthesize vitamin B12.  It is manufactured by microorganisms (bacteria, fungi and algae) and thus, is found in soil, microbial-contaminated water, and feces.  It just so happens that animals and their food byproducts are contaminated with the B12-producing bacteria, and subsequently, become a source of for it.  It may also be that some plant foods are contaminated with these bacteria, but we generally wash away any vitamin B12 prior to eating them.

The recommended intake of B12 is actually quite small (2.4mcg for those over the age of 14yrs);  but a deficiency is a very serious problem leading ultimately to irreversible nerve damage.
Fortunately, we are able to store, recycle, and reuse vitamin B12 very efficiently, and only excrete a tiny fraction from our internal stores each day.  However, over time, if we do not replenish our stores from either the food in our diet or from supplements, a deficiency may occur.

Numerous studies have demonstrated that any actual deficiencies of B12 in vegetarian or vegan diets is mainly due to poor meal planning. (Leitzmann C. 2005. Vegetarian diets: what are the advantages? Forum of Nutrition. (57) 147-56)  Obviously, any diet based on a single starchy staple (root vegetable, rice, pasta, or bread) will not only lack vitamin B12, but also protein, iron, zinc, and calcium.  The answer to the problem is super simple though, simply incorporate nutrient-rich plant foods, such as nuts, legumes, leafy greens, fortified non-dairy milk, and fortified whole-grain cereals.  This will significantly improve the bioavailability of nutrients, while also being an effective solution to bigger environmental problems and global hunger issues.

In truth, vitamin B12 deficiencies are very rare, and usually take quiet a long time to develop, anywhere from 3-15 years, and can occur in both vegans and non-vegetarians alike.  It is a condition that mostly arises from malabsorption, or a poor or highly restricted diet, or if a person has been vegan for many years without taking any form of supplementation or fortified foods.

If a deficiency goes untreated it may cause symptoms such as: weakness, a feeling of being extremely tired or light-headed, tingling or numbness in the fingers, arms and legs, nerve damage, difficulty with balance, heart palpitations and shortness of breath, pale skin, sore tongue, bruising or bleeding easily, bleeding gums, upset stomach, weight loss, reduced appetite, indigestion, and diarrhea or constipation.  

Vitamin B12 is especially important during pregnancy and lactation, as well as for infants and children.  

So, if you are incorporating the practice of ahimsa (non-harming) into your life by choosing a vegan diet, (meaning you don't eat any animal products: seafood, meat, poultry, milk, cheese or eggs) it is important to make sure you are getting enough vitamin B12, and even more so if you are planning on becoming pregnant, currently are pregnant, or breastfeeding. 

Luckily the number of vegan foods that are fortified with vitamin B12, along with other essential vitamins and minerals, has increased significantly over the past few years, and vitamin B12 from fortified foods is actually more easily absorbed then B12 from animal sources.
(Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. National Academy Press. Washington, DC, 1998)

Some Common Myths
- Nature provides every nutrient we need.  Consuming supplements or fortified foods of any kind is unnecessary if your vegan diet is truly optimal.
- Fermented foods, sprouts, mushrooms, dulse and other sea vegetables, spirulina, algae, and raw plant foods (with or without bits of dirt on them) provide plenty of vitamin B12 for people.
- You make plenty of B12 in your mouth and small intestine to supply your daily needs.
- Some vitamin B12 originating from bacteria in the large intestine goes against the current and travels upstream to the absorption site for B12 in the small intestine.
- Some people manage with no reliable dietary or supplementary source of vitamin B12
(Brenda Davis, RD and Vesnto Melina, MS, RD. 2010. Becoming Raw. 169-170)

Food Sources of Vitamin B12
- Plants do not require B12 and therefore have no mechanism to produce, absorb, or store it, so humans cannot obtain vitamin B12 from any plant sources.
- If humans are not obtaining B12 in their diet from animal sources you can easily obtain enough vitamin B12 from Fortified Plant-based foods (yeast extracts like Marmite / Vegemite, nutritional yeast, fortified breakfast cereals, soy / almond milk, fortified veggie burgers / vegetable stocks)

Nutritional Yeast is a GREAT vegan source of vitamin B12.
Here is an amazingly delicious recipe for homemade vegan macaroni & "cheese" using nutritional yeast.  Happy Cooking! 

What You Need: 
1 1/2 pounds pasta, preferably macaroni (could be gluten-free)

"Cheese" Sauce:
1 1/2 cups unsweetened nondairy milk
1 1/2 cups nutritional yeast
1 cup canola or vegetable oil
1 cup water
1/3 cup tamari or soy sauce
1/4 (12 ounce) block firm (not silken) tofu
1 tablespoon garlic powder
1 tablespoon paprika
1 tablespoon vegesal or in lack of fancy product, just use some sea salt
1 dollop mustard (optional) 

1. Preheat oven to 350 degrees Fahrenheit. Boil water in a big pot and cook pasta according to package directions.
2. Add all of the "cheese" sauce ingredients in a blender and process until smooth. Once pasta is cooked, drain and put it in the baking pan (about the size of a brownie pan). Pour the "cheese" sauce over the pasta.
3. Bake until the top of the pasta looks slightly browned and crispy, about 15 minutes.
This is very simple and tastes amazing! 
If you are cooking for yourself, it will last about 5 days if you eat it for all three meals of the day.
Preparation Time: 
about 8 minutes; Cooking Time: 15 minutes


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