Is B-12 the Only Nutrient Missing from a Vegan Diet?
Veganism is not what it’s portrayed to be in the netflix documentaries that have come out in recent years promoting it.
Forks over Knives, Game Changers, What the Health…what they all have in common is they suggest you can get nearly every single nutrient you need from plant foods. But can you? And is cutting out all animal foods really the best decision for your body, especially if you’re set out to balance your hormones?
Many who subscribe to a plant-based diet argue: “Other than Vitamin B-12, you can get all the nutrients you need from a vegan diet.” While this statement may be partially true in theory, it is highly unlikely that an individual can consume the right balance of nutrients, convert them to their usable forms, and properly absorb them while on a vegan diet.
Confusing, right? Well to understand the complexities of what a diet truly needs to keep us healthy, we need to break down the difference between essential and non-essential nutrients. Non-essential nutrients can be made by the body (under the right circumstances), while essential nutrients can only be obtained from food. This is where the impacts of a vegan diet get complicated, as this diet may be missing or low in some of the nutrients that allow the body to manufacture non-essential nutrients. Beyond diet, some individuals are already predisposed to having a difficult time converting certain nutrients for reasons we will discuss in more detail later.
Let’s explore where these complications happen when it comes to protein, fatty acids, fat-soluble vitamins, and minerals.
But first, I’ll sum it up briefly for those who are short on time:
Protein: We need specific nutrients for our bodies to create non-essential amino acids. If we are lacking these nutrients due to veganism or general lack of nutrition, we may suffer from decreased physical and cognitive performance, mood imbalances, and fertility challenges.
Fatty acids: Factors like sex and genetics can influence how well—if at all—a person converts omega-3s found in plants to the omega-3 fatty acids DHA and EPA which are critical for managing inflammation.
Fat-soluble vitamins: Real Vitamin A exists only in animal foods. Conversion of carotenes in plants to Vitamin A is compromised in children, infants, those with certain genetic polymorphisms, and people with diabetes and low thyroid function—collectively, a large percentage of the population! Vitamin D and K2 are also primarily found in animal foods.
Minerals: Iron, calcium, and zinc (all important for hormone production) tend to be harder to obtain on a plant-based diet. Typical vegan sources of minerals like seeds, nuts, grains, and legumes must be properly-prepared to maximize absorption. People on plant-based diets or people who don’t consume enough zinc in general may not be able to produce enough hydrochloric acid which can compromise protein digestion.
Protein
Proteins are the building blocks of life. They are involved in almost every function of the body, including but not limited to manufacturing cells, enzymes, hormones, and neurotransmitters. Certain plant foods can provide a decent amount of protein, but it is important to consider the quality of the protein. Nine of the twenty amino acids are considered are essential, all of which can be found to some degree in plant foods. But what about all of the other “non-essential” amino acids?
Let’s take taurine, for example. Taurine is an amino acid that is important in metabolism and phase 2 detoxification (super important for estrogen balance!) Not only that, but taurine has a calming effect on the brain and helps reduce stress. Taurine supplementation has been shown to reduce the symptoms of those struggling with mental illness.[1] Taurine can be made from an amino acid called cysteine only if there is enough Vitamin B6 to facilitate the conversion. Vitamin B6 is abundant and highly absorbable in animal foods, but not as bioavailable when it comes from plant foods.[2] Deficiency in B6 coupled with an avoidance of animal foods can set an individual up for low taurine status.
Now let’s touch on carnitine, an amino acid obtained primarily from red meat. It plays a key role in converting fatty-acids into energy. Carnitine can be made by the body if sufficient Vitamin C, vitamin B6, vitamin B3, iron, lysine, and methionine are present.[3] A plant-based diet that lacks sufficient quantities of these vitamins, minerals, and amino acids may result in carnitine deficiency, and therefore, a compromised ability to break down fats into fuel.
Finally, arginine is a non-essential amino acids that improves blood flow to the uterus and ovaries, thereby increasing endometrial thickness and egg quality in women. The body can synthesize it on its own, but requires other nutrients to do so,
The benefit of eating meat, eggs, and dairy is that we don’t have to worry about synthesizing amino acids because we are fueling our body with these nutrients directly. When it comes to balancing your hormones, amino acids are CRITICAL for estrogen balance, metabolism, uterine and egg health, among many more important physiological functions.
Fatty Acids
Now let’s talk about fatty acids. There are only two that are considered essential (there’s that word again!) They are Linoleic acid (LA) and Alpha-linolenic acid (ALA). Linoleic acid, an omega-6 fatty acid, is easy to obtain from plant foods like peanuts, corn, sunflower and sesame seeds, oat germ, wheat germ, and rice bran. Alpha-linolenic acid, an omega-3 fatty acid, can be found in flaxseeds, chia seeds, and pumpkin seeds. This sounds good for the vegan argument, but there are two more omega-3 fatty acids to take note of— DHA and EPA.
DHA and EPA are not considered essential because under the right conditions our bodies can manufacture them from ALA. This is an unfortunate categorization, as conversion of ALA from plant foods to EPA and then to DHA is inefficient and unreliable. This study by the University of Oregon revealed that, “in healthy young men 8% of dietary ALA was converted to EPA and 0%-4% was converted to DHA” and “In healthy young women, approximately 21% of dietary ALA was converted to EPA and 9% was converted to DHA.” [8]
Ability to convert ALA from plant foods into EPA and DHA is influenced by sex and genetics. But why are these two fatty acids, found in cold water fish like salmon and sardines, so important anyways?
The simple answer is is that EPA and DHA play a major role in brain health and the body’s anti-inflammatory response. Overconsumption of sugar and rancid fats (e.g. industrially-processed vegetable oils) has caused many of us to become chronically inflamed. Other contributors to inflammation include stress, air and water pollution, and toxic compounds in our toiletries, cosmetics, and cleaning supplies.
Inflammation is implicated in a wide variety of conditions— from depression to autoimmune disease to heart disease. [9] [10] Within this context, it becomes clear that we should strive to supply our bodies with sufficient EPA and DHA so they can do their jobs protecting us from the damaging effects of inflammation.
Avoiding grass-fed meat, eggs, dairy, and seafood means that your diet contains zero EPA and DHA, and that you’re solely relying on your body’s ability to make the appropriate conversion.
Fat-soluble Vitamins
The fat-soluble vitamins A, D, and K2 are found primarily in animal foods. Vitamin A is found exclusively in animal foods. Mushrooms are the only plant source of Vitamin D, and K2 is found inconsistently in some fermented vegetables. Yes, your body does have the ability to convert K1 to K2 in the gut, but only if your gut is healthy enough to do so!
Sufficient Vitamin A status is crucial for good vision, healthy skin, strong immunity, and fertility. Retinol is the name for the usable form of vitamin A, abundant in liver and also found in butter, egg yolks, cheese, and some fish. While many people believe you can get Vitamin A from leafy greens and orange vegetables, the truth is these only contain carotenes.
Under optimal circumstances, the body can transform every six units of carotenes into one unit of Vitamin A. But diabetics, individuals with low thyroid function, children, and babies all have a compromised ability make this conversion. People with genetic polymorphisms in the BCMO1 gene also have significantly impaired ability to convert beta-carotene into retinol. This affects about 45% of the population to some degree. Considering the wide variety of conditions that can impact the utilization of carotenes, eating preformed Vitamin A from animal foods is the best way to ensure appropriate intake.
Vitamin D is another nutrient many of us today are lacking. Our bodies can manufacture Vitamin D from the sunlight, but our modern, primarily indoor lifestyles prevent many of us from getting enough sun exposure. People who live in the northern latitudes and those with more pigmented skin are further disadvantaged when it comes to converting sunlight into Vitamin D.
The good news is that we can consume nutritious (and delicious) animal fats, which contain not only Vitamin D, but also Vitamin A and Vitamin K2. These three nutrients work together synergistically, with increased health benefits when consumed together. For example, Vitamin D and K2 play a key role in bone health, ensuring the proper absorption and utilization of dietary calcium.[11] [12] One would have to eat over a cup of mushrooms every single day to meet their Vitamin D requirements on a plant-based diet. Instead, we can consume high-quality animal fats and organ meats like liver to guarantee sufficient intake of all three of these critical fat-soluble vitamins. Check out my post on saturated fats and cholesterol to better understand why they belong in a healthy diet.
Minerals
We can’t underestimate the role that minerals play in the body. They serve as cofactors for enzyme reactions, meaning every chemical reaction that takes place inside our bodies requires minerals.
There are three main minerals to pay close attention to while on a vegan diet: iron, calcium, and zinc.
Iron is one of the most common nutrient deficiencies worldwide, among vegans and non-vegans alike. It’s crucial for the health of the thyroid which produces hormones involved in ovulation. Although some iron can be found in foods like spinach and raisins, its more absorbable form (heme-iron) is found exclusively in animal proteins.
When it comes to calcium, many claim seeds and leafy greens can provide ample amounts. However, women of childbearing age require at least 1,000 mg per day. For reference, only about 80mg of calcium are absorbed from one cup of cooked bok choy. Consuming quality grass-fed dairy in the forms of milk, cheese, and yogurt makes reaching the Recommended Daily Amount for calcium much more feasible.
Zinc is a key mineral involved in immune function, wound healing, and progesterone production. Legumes and pumpkin seeds are the primary vegan sources of zinc, but often they are not prepared properly to promote optimal absorption. Beans, grains, nuts, and seeds contain phytic acid, an antinutrient that binds to minerals in the gut. Everyone, but especially plant-based eaters, should soak, sprout, or ferment these foods to ensure the bioavailability of the nutrients they contain.
A wide variety of problems can arise from zinc deficiency, but I would like to touch on two in specific:
First, low zinc status can impair the digestion and utilization of dietary proteins. This occurs because zinc is a necessary co-factor for the production of hydrochloric acid, responsible for breaking down protein in the stomach. This is a common cause of digestive discomfort, but it can be particularly worrisome for a population that may have more difficulty meeting its protein needs.
Second, plant-based diets are also typically much higher in copper than zinc, which can cause imbalances between the two minerals. Copper and zinc are antagonists, so when a person avoids high zinc foods like red meat, he or she is at risk of accumulating copper. Too much copper in the body can lead to estrogen dominance.[13]
To Wrap it all up…
Theoretically, if an individual were excellent at converting nutrients (for example, carotenes to Vitamin A; ALA to EPA/DHA), they may be able to receive nearly adequate nutrition from a well-planned, properly-prepared plant-based diet— with the exception of B12.
But because a majority of the nutrients discussed throughout this post are more absorbable and/or more accessible in animal foods, I find it unnecessarily risky to attempt to obtain them exclusively from plant foods.
I do not intend to discount the numerous benefits many people share that they experience on a vegan diet. Many report immediately feeling more energy when cutting out meat and dairy. But it is difficult to isolate the absence of animal foods as the only meaningful variable. Oftentimes, those who turn to plant-based diets will simultaneously cut out soda and other highly processed foods and increase the amount of fresh fruits and vegetables they consume. Also, people with low stomach acid and bile production might experience an improvement in their digestive discomfort when they cut out heavy animal foods. But avoidance of meat is a band aid solution, and it’s important to address why their digestion may have been compromised in the first place.
In Vegetarianism Explained, Dr. Natasha Campbell-McBride asserts that plant foods are generally cleansing foods and animal foods are generally building foods. A temporary vegan diet, which she classifies as a type of fast, can be useful for detoxification.[14] Because it can take time for nutrient stores to be depleted, the symptoms of nutrient deficiencies may not manifest right away. Dr. Campbell McBride contends that a vegan diet should only be used therapeutically for a limited period of time.
Recommendations
I applaud plant-based eaters for their determination to eat ethically and in accordance with their beliefs. Giving up so many foods isn’t easy, and I admire the good intentions of those who choose to do so. For anyone looking to limit their consumption of animal foods but is willing to include some in moderation, I have a few recommendations.
Raw dairy and fermented milk products, butter, and pastured eggs provide many of the nutrients listed above (like amino acids, minerals, and fat-soluble vitamins.) Anyone looking to further safeguard their health while minimizing animal products might consider investigating a local source of liver. Liver is one of the most nutrient-dense parts of the animal, and one to two servings per week could be enough to prevent serious nutrient-deficiencies. It’s an amazing source of heme iron, B vitamins, Vitamin A, and it even contains the fatty acids EPA and DHA.
Vegans and conscious omnivores like myself have a lot more in common than it might appear on the surface. We are disturbed by the horrific treatment of factory farmed animals and the environmental impacts of industrial agriculture. We choose to opt out of this system.
Fortunately, there is an alternative. We have the option to support small local farmers who raise their animals with love and compassion, giving them the freedom to roam outdoors and eat the foods that they evolved to eat. When we nourish our bodies with the food these animals provide, we can still experience a deep reverence for them. We can allow ourselves to be humbled and feel immense gratitude for their sacrifice.
In the end, how we choose to fuel our bodies is a deeply personal matter. We all must choose the diet that serves us best—one that nourishes us physically and aligns with us philosophically. It is helpful to be equipped with information about the potential risks and rewards of any diet, so that we make informed and empowered decisions about our health.