Vegan Vitamin B12 – Sources, Absorption, Supplements and Deficiency

Vegan Vitamin B12

Vitamin B12, also known as cobalamin, is one of the thirteen essential vitamins that the body requires to survive. It is involved in many crucial processes, including (1) creating DNA, cell division and, maintaining and repairing Myelin Sheath (a protective coating around nerve cells). Unfortunately, there are limited vegan vitamin B12 sources as plant based foods do not naturally contain this vitamin. 

Animal products including meat, chicken, fish, eggs and dairy products are rich in this vitamin.

Consuming enough B12 is crucial for proper blood and brain function and it can be stored in the liver for many years. Deficiency can lead to a range of health consequences including nerve damage and pernicious anaemia. 

It is important for those following a vegan or vegetarian diet ensure they are getting enough each day through foods or supplements.

This article explores vitamin b12 on a vegan diet, where you can find it, supplement recommendations and how to avoid deficiency.

What does Vitamin B12 Do In The Body?

Vitamin B12 is an essential nutrient that almost every cell in the body requires for proper functioning. It is involved in two main biochemical processes in the body and acts in two main forms – methylcobalamin and adenosylcobalamin. Each of these forms have a different role.

Methylcobalamin acts as a cofactor to the enzyme methionine synthase, which catalyses the transfer of a methyl group from N-methyltetrahydrofolate to homocysteine, yielding methionine and tetrahydrofolate. This reaction occurs in the cell cytoplasm (2).

From methionine, S-adenosyl-methionine is formed, which is a universal methyl donor for many important substrates, including DNA, RNA, hormones, proteins, and lipids. This reaction is also important as it converts methyltetrahydrofolate to tetrahydrofolate, the active form of folate, which is another essential B-vitamin.⁠

Adenosyl cobalamin acts as a cofactor in the methyl-malonyl CoA mutase transformation of methyl-malonyl CoA into succinyl CoA in the mitochondria (2). ⁠

How is it absorbed?

The absorption of vitamin B12 contains a number of steps.

In animal based foods, it is found in the form of methyl-, deooxyadenosyl-, or hydroxy-cobalamin.

When this form of B12 nutrition reaches the stomach, two digestive enzymes – pepsin and hydrochloric acid break down the binding protein, releasing the cobalamin portion of the nutrient known as “free vitamin b12”.

When synthetic (man made) B12 is added to fortified food or supplements, it is already in its free form and therefore does not require this separation step.

Free vitamin b12 then combines with Intrinsic Factor (IF). IF is a type of protein secreted by parietal cells in stomach. This complex is then able to be absorbed in final section of the small intestine known as the illeum.

Absorption can also be influenced by age, reduced gastric acidity and other gut disorders.

This vitamin also has many inactive analogues. These are molecules that look like its active form, but actually are not, and can interfere with it’s function and absorption.

How much vitamin B12 can be absorbed at once?

Vitamin B12 absorption depends on how much is consumed at one time. When added to foods such as soy milk or veggie delight sausages in low amounts (less than 5 mcg per dose) it has a similar absorption rate to animal products. It is absorbed at approximately 56% of a 1mg dose.

Meaning, if you drank a glass of Sanitarium So Good Soy milk which contains 1mcg per cup, you would only be able to absorb approximately 0.5mcg.

Some brands of plant based milk are fortified with vitamin B12

 

However, absorption decreases significantly with high doses of B12. Doses above 500mcg have absorption of 1% or less.

This means, that if you take a supplement of 500mcg, you’re only able to absorb 5mcg at one time.

How Much Vitamin B12 Do I Need?

How much you require each day is based on the Recommended Daily Intake (RDI). The RDI is the average daily dietary intake that meets the nutrient needs of 97-98% of the population.

A summary of the  RDI for vitamin B12 based on the Nutrition Reference Values for Australia and New Zealand (2):

For children under 12 months of age the RDI cannot be determined and therefore Adequate Intake (AI) is used.  The AI is based on the average daily nutrient intake deemed to be adequate based on estimates of healthy groups.

The nutrient reference values (NRVs) for Infants is measured by adequate intake (AI) and is outlined above (2):

Vegan Vitamin B12 Food Sources:

Our bodies can not create B12, meaning that it must be eaten in the diet. 

Vitamin B12 is bound to protein. It is found in all animal foods with the exception of honey.  This includes meat, poultry, fish, eggs and dairy products (3).

Individuals who follow plant-based diets must rely on fortified foods and supplements to meet their daily requirements.

Vegan vitamin B12 food sources include:

  • Certain plant-based milks (i.e. Sanitarium soy milk)
  • Nutritional yeast
  • Reduced salt Vegemite (note: the original vegemite is not fortified with B12)
  • Certain meat substitutes (i.e. Vegie Delights products)

If you are wanting to meet your daily needs through fortified foods it is essential that you read the ingredients list and nutritional panel as not all products listed above will be fortified with this nutrient.

Products fortified with vitamin B12 will have this listed on the nutrition panel

It is also important to note that nutritional yeast, also known as savoury yeast flakes, may not be a reliable source. The vitamin levels contained within nutritional yeast can vary between brands, meaning it is not recommended as a sole source B12.

The table above outlines the vegetarian and vegan vitamin B12 food sources (4):

If you want to try and meet your requirements through food alone you will need to consume 2-3 servings of fortified foods, at least 4 hours apart for optimal absorption. 

The number of servings required daily will vary depending on which fortified products you consume. Due to this not being feasible for many individuals, it may be beneficial to consider a vegan vitamin b12 supplement.

Poor Sources of Vitamin B12

Some vegan foods claim that they contain B12. This includes tempeh, seaweed, organic foods and spirulina. Unfortunately these contain inactive analogues. This means, when analysing these compounds in the lab they may look like vitamin B12, but they are not biologically active meaning humans cannot absorb them. 

Signs of Vitamin B12 Deficiency

Deficiency can be common amongst vegans and those following a mostly plant-based diet. 

Sign of vitamin B12 deficiency include (3):

  • Megaloblastic anemia, meaning red blood cells are not produced properly and are larger than normal
  • Fatigue
  • Weakness
  • Constipation
  • Loss of appetite
  • Weight loss
  • Numbness
  • Tingling of the hands and feet

Signs of deficiency in infants include (7):

  • Failure to thrive
  • Movement disorders
  • Developmental delays
  • Megaloblastic anemia

A 2013 systematic review investigating the prevalence of deficiency among vegetarians and found rates of 62% amongst pregnant women; 32% amongst vegetarians; and 30% to 76% amongst vegans (depending on the definition of deficiency) (6) 

Normally, anaemia is the first symptom of deficiency to occur. Often deficiency can go undetected in vegans as it is masked by high intakes of folate, found in fruits, vegetables and wholegrains (3). If someone’s diet is high in folate and low in B12, the folate will “mask” the anemia and nerve damage will be the first symptom to occur.

Although textbooks and articles state that deficiency can take 2-5 years, our dietitians have seen deficiency occur in as little as 6 months. It is essential to commence supplementation or ensure you are eating adequate amounts as soon as you adopt a completely plant based diet

It is also important for plant-based eaters to regularly check their blood status. Failure to do so can increase the risk of irreversible brain and nerve damage. 

Should vegans supplement Vitamin B12?

Even though there are some plant-based foods fortified with B12, the selection is quite limited and these foods need to be consumed daily to meet the RDI. 

For this reason it is often recommended that those that follow a largely plant-based diet, consider taking vegan Vitamin B12 supplements. 

To work out an appropriate supplement regime for you, book in for a consultation with one of Plant Nutrition and Wellness’s plant-based dietitians

 

 

References

(1)  The Medical Journal of Australia – Vitamin B12 and Vegetarian Diets

(2)  Nutrient Reference Values – Vitamin B12

(3)  National Institute of Health – Vitamin B12

(4)   Food Standards Australia New Zealand. NUTTAB 2010 online searchable database

(5)  https://vegemite.com.au/product/

(6)  How prevalent is Vitamin B12 deficiency among vegetarians?

(7)  Homocysteine and methylmalonic acid in diagnosis and risk assessment from infancy to adolescent

(8) Biochemistry of B12-Cofactors in Human Metabolism 

 

This article was co-written by Plant Nutrition and Wellness’s founder Kiah Paetz and Intern Tessa Funk. You can connect with Tessa on linkedin here.

How do you build muscle on a vegan diet?

Everything you need to know about meal timing, protein requirements, calorie needs and vegan food ideas by Vegan Sports Nutritionist Leah Higl

The core principals used to build muscle on a vegan diet is very similar to an omnivorous diet.

In my time working with a range of athletes and weekend warriors, there are a number of areas I see vegans struggle with. These, in turn, can reduce their ability to reach optimal performance.

These include:

  • Not eating enough calories to reach their athletic goals
  • Having lower protein intakes than what is optimal for building muscle
  • Not optimising what foods they are eating in and around their training.

 

Here are my three biggest tips to build muscle on a vegan diet!

Leah Higl is the Vegan Sports Dietitian at the PNW Clinic

1. To build muscle you need to eat sufficient calories

There are two major factors that are important for anyone (vegan or not) trying to get bigger and stronger. Without these, gaining muscle is near impossible or at the very most, extremely slow.

Firstly, it is essential to have a resistance training program that is targeted to muscle growth. Secondly, it is important to eat enough calories to promote physiological adaptations (muscle growth) from the program.

What are calories?

Calories are a unit of measurement that describes the energy in food. This is our energy input. The body also burns a certain number of calories through physiological processes keeping you alive. This is our energy output and is known as our basal metabolic rate or BMR.

Additional calories are burnt performing any kind of activity such as standing, walking, eating food and doing structured exercise. The more you move, the more calories you burn. The total sum of all the calories you burn daily is known as your total daily energy expenditure (TDEE).

In order to gain muscle on a vegan diet, it is recommended that you eat in a caloric surplus. This means, eating more calories from food than your TDEE.

 

Building muscle in a very energy-intensive process. Without consuming a sufficient amount of calories, your body will not have enough energy to build lean body mass.

 

How much more calories do I need to build muscle?

The amount of calories to help muscle synthesis (growth) differs from person to person. However, it typically falls around 300-500 calories or 10% above the individuals TDEE (1).

 

2. Optimise your protein intake

Meeting your protein needs is one of the most important nutrients to consider when building muscle on a vegan diet.

Protein is a macronutrient, alongside fats, carbohydrates and fiber.

Tofu is a rich source of plant based proteins

When I tell people that I am a powerlifter and that I am also vegan, I will immediately get the question “But where do you get your protein from?”.

When having a varied vegan diet, it is quite easy to meet your basic body requirements for protein. Vegan protein sources include legumes and beans, nuts and seeds, tofu, tempeh, seitan, textured vegetable protein and wholegrains.

However, getting enough protein to maximise muscle protein synthesis requires a lot more planning. In fact, I find that many vegan athletes and gym-goers are not meeting the recommended amount of protein to facilitate increases in lean body mass.

 

It is recommended that people looking to increase their muscle mass should consume anywhere between 1.6 and 2g of protein per kilo of body weight per day (2).

 

For an athlete that weighs 80kgs this would equate to 128-160g of protein daily. That’s a fair chunk of protein to consume every day as a vegan, but it is far from being impossible.

To meet these recommendations:

  • Incorporate a protein-rich food in every meal and snack throughout the day including tofu, tempeh, soy milk, edamame, textured vegetable protein (TVP), seitan, legumes, nuts and seeds
  • Aim for at least 30-40g of protein in main meals and 15-20g of protein in snacks
  • Utilise higher protein wholegrains such as a high protein bread and pasta with a higher protein content such as chickpea or soybean pasta.
  • Supplement with a vegan protein powder (if needed)
  • Eating enough protein to optimise muscle gain is a little trickier on a vegan diet than it is on an omnivorous diet but with some extra planning and knowing your way around a block of tofu it can become simple.

 

3. Fuel your training properly

Once you have managed to lock down your calorie intake and protein intake, it is time to take a look at what you are eating around your training.

 

Want to make sure that you’re always getting eating the right foods to maximise muscle growth? Why not book a consultation with our sports nutritionist Leah.

 

Proper pre and post-training nutrition is essential for ensuring you are:

  • Going into every training session well-fuelled for optimal performance
  • Recovering adequately after each session to promote physiological adaptations (muscle growth) to training

We discussed the importance of the macronutrient protein above. However, when fuelling our training the macronutrient carbohydrates is also important to consider.

Carbohydrates are found in fruits, starchy vegetables (potato, corn, sweet potato), rice, pasta, quinoa, crackers and bread. Ideally, your pre-training meal should be 2-3 hours before your session with the option of having a small snack 1-2 hours prior to training.

For a pre-training meal go for something:

  • Rich in carbohydrates to prime your fuel stores
  • Moderate in fibre to avoid gastrointestinal discomfort
  • Low in fat (higher fat meals take longer to digest) (3)

Easy meal ideas include:

  • Soy yoghurt with muesli
  • Fried rice with tofu and vegetables
  • Sandwich with salad and seitan
  • Pasta with vegetables and chickpeas

 

A sandwich is an easy pre-training meal

Easy snack ideas include:

  • Rice cakes with hummus
  • Overnight oats
  • Dried or fresh fruit

After training, additional food should be consumed within the first couple of hours after finishing your session.

This meal should be rich in:

  • Carbohydrates to replenish energy stores
  • Protein to promote muscle protein synthesis (4)

Post-work-out meal ideas include:

  • Smoothie with soy yoghurt or protein powder and fruit
  • Tofu stir fry with brown rice
  • Lentil dal with rice
  • TVP bolognaise with pasta

Take-home tips

To maximise building muscle on a vegan diet make sure to keep a note of the following:

  • Consume 300-500 calories or 10% above your total daily energy expenditure
  • Consume 1.6-2g of protein per kilo of bodyweight per day
  • Have a carbohydrate rich meal or snack 1-3 hours before training
  • Have a protein and carbohydrate rich meal within 2 hours after training

This article was written by Plant Nutrition and Wellness’s resident sports nutritionist Leah Higl. If you’re following a plant-based or vegan diet and want to make sure you’re meeting all your nutritional needs, take control and apply to work with one of our expert plant-based dietitians.

 

References

1. Slater GJ, Dieter BP, Marsh DJ, Helms ER, Shaw G and Iraki J. (2019). Is an Energy Surplus Required to Maximize Skeletal Muscle Hypertrophy Associated With Resistance Training. Front. Nutr, 6,131. doi: 10.3389/fnut.2019.00131

2. Rogerson D. (2017). Vegan diets: practical advice for athletes and exercisers. Journal of the International Society of Sports Nutrition, 14, 36. https://doi.org/10.1186/s12970-017-0192-9

3. Sports Dietitians Australia. (2018). Eating and Drinking Before Exercise . Retrieved from Sports Dietitians Australia: https://www.sportsdietitians.com.au/factsheets/fuelling-recovery/eating-drinking-sport/

4. Sports Dietitians Australia. (2019). Recovery Nutrition . Retrieved from Sports Dietitians Australia: https://www.sportsdietitians.com.au/factsheets/fuelling-recovery/recovery-nutrition/

 

#vegan #proteinneeds #sportsnutrition #veganprotein

Vegan Zinc – Sources, Absorption, and Deficiency

Why zinc is important for vegans

Zinc is an essential nutrient to consider when following a vegan or vegetarian diet. It is a mineral that is distributed throughout all our body tissues and fluids. It is necessary for our body to perform a variety of important functions (1).

Some of these include:

  • Immune support and wound healing
  • Metabolism
  • Regulation of gene expression and DNA synthesis
  • Supports normal growth and development during childhood, adolescence, and pregnancy

 

Zinc requirements for vegans

Those following a vegetarian or vegan diet have higher requirements for certain vitamins and minerals than those specified for the general healthy population. These include the minerals iron and zinc.

Zinc is one of these nutrients as plant-based sources have a lower bioavailability than animal-based sources such as red meat and dairy. In other words, it is harder for our bodies to absorb this nutrient from plant-based foods.

 

It is recommended that those following a vegan/vegetarian or predominantly plant-based diet consume 150% of the recommended daily intake for the general population to ensure requirements are met.

 

Below is a summary of the daily requirements for vegetarians/vegans based on 150% of the values provided in the Nutrient Reference Values for Australians and New Zealanders(2).

Zinc RDI for Vegans

There is no difference in the RDI between older adults (70 years+) and those in their early stages of adulthood. See zinc requirements for those following a non-vegetarian or vegan diet here (4).

 

Want to make sure that you’re always getting enough zinc in your diet? Why not try one of our male or female vegan meal plans!

Cashews are a fantastic source of zinc

Best vegan sources of zinc

Zinc is present in a variety of plant-based foods. A well-planned vegetarian or vegan diet is more than adequate to meet your requirements.

It can be found in high concentrations in the outer layers of grains. As such, the best plant-based sources are minimally refined wholegrain products such as rolled oats, brown rice, and wholegrain bread and cereals.

Vegan zinc sources include nuts and seeds, legumes, soy products such as tofu and fortified breakfast cereals(1).

 

The following table lists the amounts found in different plant-based foods (3):

Zinc content of plant based foods

It is recommended that you include a variety of these foods in your diet on a daily basis.

 

This may look like:

Breakfast: ~4mg

½ cup oats + 1 cup soymilk + 30g pumpkin seeds + berries

Lunch: ~6mg

2 slices wholegrain bread + 2 tbsp hummus + ½ cup salad + 15g sundried tomato + 100g sliced tempeh

Dinner: ~6.5mg

Tofu stir fry (with 150g tofu, 30g cashews, 2 cups mixed vegetables) + ½ cup brown rice

Snacks: ~5mg

30g pecans, 1 apple, hot chocolate (2tbsp cocoa, 1cup soymilk, 1tsp sugar), 4 wholegrain crackers + 2tbsp tahini + tomato

TOTAL: 21.5mg total

 

Optimising zinc absorption

Plant-based sources of zinc are not as readily absorbed by the body. This is due to the presence of inhibiting compounds in foods that reduce absorption.

The main inhibitors are phytates which are commonly found in wholegrains and legumes.

This effect can be overcome by food-processing techniques such as the fermentation of whole grains and soaking legumes and sprouting seeds and grains.

Additionally, taking iron supplements close to meals can also inhibit the absorption of zinc as the two nutrients compete for uptake (1,4).

Foods that contain high amounts of protein are also a good choice to consider as protein binds to zinc and increase zinc absorption.

 

Read about meeting your protein needs on a vegan diet here

 

Some simple ways to improve vegan zinc absorption include:

  • Opting for yeast-leavened or sourdough bread
  • Pre-soak and rinse legumes before cooking

  • Opting for sprouted grains and seeds

  • Consume iron supplements away from meals

  • Include foods high in both zinc and protein such as legumes, tofu, tempeh and nuts

 

Signs of a zinc deficiency

Cases of deficiencies are rare in developed countries due to our abundance of access to zinc-rich foods however they are still possible.

The main reasons for developing a deficiency include poor dietary availability paired with an increased requirement during periods of growth and development or periods of stress, infection and acute trauma(2).

 

Signs of a deficiency to look out for include:

  • Reduced growth rate in children

  • Suboptimal pregnancy outcomes

  • Increased susceptibility to illness and infections

  • Poor wound healing

  • Impaired taste perception

 

Is being vegan a risk factor for developing a zinc deficiency?

No, despite differences in food choices, vegetarians and vegans tend to have similar blood levels of zinc to non-vegetarians.

Over time, the body is able to adapt to the lower bioavailability of zinc in plant-based diets by increasing the efficiency in which it is able to absorb this mineral and reducing losses out of the body. Therefore, those following a plant-based diet are at no greater risk (1).

If you are concerned you may have a zinc deficiency it is important to discuss any concerns with your GP.

 

Should vegans supplement zinc?

It is absolutely possible to meet your requirements from solely food sources when following a plant-based or vegan diet. This is always preferred over supplement use.

Whilst there is no evidence of adverse effects from consuming high amounts of zinc naturally occurring in food, excess zinc intake from long term high doses of zinc supplements may result in negative side effects. This includes negatively affecting the immune system , lowering HDL (also known as good cholesterol) levels and copper deficiency.

There are a variety of forms of zinc available in supplements. These include zinc acetate, sulfate, picolinate, monomethionine, gluconate, glycinate, orotate and citrate.

There is an upper limit of total zinc intake of 40mg/day from food and supplements (including fortified foods) and any supplementation should proceed with caution(2).

To reduce the risk of having excess zinc supplementation, it is important to seek medical advice from your GP before commencing and supplements.

 

References

  1. Medical Journal of Austral – Zinc and Vegetarian Diets

  2. Australian Nutrient Reference Values – Zinc

  3. Food Standards Australia and New Zealand

  4. Considerations in planning a vegan diet: Children

 

If you’re following a plant-based or vegan diet and want to make sure you’re meeting all your nutritional needs, take control and apply to work with one of our expert plant-based dietitians. .

This blog was co-written by student dietitian by Georgia D’Andrea. You can connect with Georgia on Linkedin.