How to Supplement a Plant-Based Diet

Written By Matt Tullman

Choosing a plant-based diet can be a powerful step towards better health and a more sustainable lifestyle. You load your plate with vibrant fruits, vegetables, and whole grains, feeling energized and aligned with your values. 

But as you embrace this way of eating, a question often emerges: 

Are you getting everything your body needs to truly thrive? 

The truth is, while a whole-food, plant-based diet is rich in many nutrients, some are harder to get from plants alone. This isn't a flaw in the diet… 

It's simply a matter of biology and modern food systems. Addressing these potential gaps is the key to moving from just surviving to thriving on a plant-based journey. This guide will walk you through the essential nutrients for vegans, vegetarians, and plant-forward eaters, and explain how to supplement a vegan diet or plant-based diet for optimal health.

Why Even a Healthy Plant-Based Diet Needs Complements

You might hear that you can get all your nutrients from plant foods, and for the most part, that’s true. 

A well-planned plant-based diet provides abundant fiber, phytonutrients, and most vitamins and minerals. However, a few key nutrients are either not found in plants or are not easily absorbed from plant sources.

That’s why we recommend you complement your diet. 

Think of it this way: a complement is something that completes or brings to perfection. It’s not about adding more of the nutrients you already get from your food. 

Instead, it’s about thoughtfully filling in the specific gaps to ensure your body has everything it needs for long-term wellness. 

Focusing on these nutritional needs on a plant-based diet helps you maintain energy, support your immune system, and protect your long-term health.

The Essential Nutrients for Vegans and Plant-Forward Eaters

Let's explore the specific nutrients that deserve your attention and why they are so important.

1. Vitamin B12: The Non-Negotiable Nutrient

If there’s one supplement every person on a plant-based diet needs, it's Vitamin B12. This vitamin is crucial for nerve function, DNA synthesis, and the formation of red blood cells. A long-term deficiency can lead to serious neurological issues and anemia, and research continues to highlight its importance in vegan diets (see this PubMed review; randomized trial on ScienceDirect).

• The Challenge: Vitamin B12 is produced by bacteria in the soil and the gut of animals. Modern sanitation practices mean we can't rely on unwashed vegetables for it, and it's not naturally present in plant foods.
• The Solution: While some foods like nutritional yeast are fortified with B12, relying on them daily can be inconsistent. A dedicated B12 supplement provides a reliable, precise dose to keep your levels optimal.

Vitamin D3: The Sunshine Vitamin

Vitamin D plays a critical role in immune function, bone health (by helping absorb calcium), and gene expression. Numerous studies show that people who follow a plant-based diet may be at greater risk of deficiency, especially those with limited sun exposure (NCBI study). Maintaining healthy vitamin D levels helps protect against bone loss and supports muscles and immunity (NHS resource).

• The Challenge: Our bodies synthesize Vitamin D when our skin is exposed to sunlight. However, factors like season, latitude, skin tone, and sunscreen use limit our production. While some animal products contain Vitamin D, plant-based sources are scarce.
• The Solution: Look for a high-quality, vegan Vitamin D3 supplement. D3 (cholecalciferol) is the form your body produces from sun exposure and is generally more effective at raising blood levels than other forms.

Omega-3s (DHA & EPA): Brain and Heart Health Heroes

You’ve likely heard about the importance of Omega-3s. While plant sources like flax, chia, and walnuts provide ALA (alpha-linolenic acid), your body is very inefficient at converting it into the more complex forms: DHA and EPA. These long-chain fatty acids are vital for brain health, cardiovascular function, and controlling inflammation.

Research consistently finds that people following plant-based diets often have lower blood levels of DHA and EPA compared to those who eat fish, which can influence long-term heart and brain health (Serum 25-hydroxyvitamin D status of vegetarians, partial vegetarians, and nonvegetarians). Other studies highlight how supplementing with algae-derived DHA/EPA can effectively raise omega-3 status to levels comparable to fish eaters—without needing to consume animal products.

• The Challenge: The primary source of DHA and EPA is fatty fish, which get it from eating microalgae. Relying solely on ALA from seeds and nuts often isn't enough to meet your body's needs for these critical fats.
• The Solution: An algae-derived DHA/EPA supplement is one of the best supplements for a plant-based diet. It provides a direct, clean source of these essential fatty acids without the need for fish and is backed by research as an effective way to optimize omega-3 intake for vegans and vegetarians.

Other Nutrients to Keep on Your Radar

Beyond the big three, there are several additional nutrients that deserve focused attention for anyone eating a plant-based or plant-forward diet. Optimizing these ensures your body is truly thriving.

• Iodine: Essential for healthy thyroid function and metabolism, iodine can be inconsistent in a plant-based diet. While some sea vegetables provide iodine, intake can fluctuate widely, and many people have shifted to sea salts that lack added iodine. Deficiencies are subtle but can impact energy, focus, and metabolic health.
• Zinc: Zinc is crucial for immune health, cellular repair, and enzyme function. Although legumes, seeds, and whole grains contain zinc, they also have phytates—natural compounds that reduce zinc absorption. Studies like this one on zinc bioavailability explain how phytic acid can make it difficult to meet your needs from food alone. Techniques like soaking, sprouting, or fermenting can help a bit, but the gap can remain, especially for athletes and active individuals whose zinc requirements may be higher. Some experts suggest vegans may need up to 50% more zinc than omnivores to achieve optimal absorption (Vegan Health).
• Vitamin K2: Unlike Vitamin K1 found in leafy greens, Vitamin K2 is predominantly present in certain animal foods and fermented products like natto. K2 works alongside Vitamin D to ensure calcium ends up where it belongs: in your bones and teeth, not your arteries. There are emerging studies linking higher K2 intake with improved cardiovascular health and lower risk of arterial calcification (NCBI PMC). Because K2 is so scarce in most Western plant-based diets, supplementation or inclusion of specific fermented foods may be wise.
• Selenium: Selenium is a potent antioxidant, supporting thyroid activity and immune function. Brazil nuts are an excellent plant-based source, but the selenium content varies wildly depending on soil conditions, so consistency is tough (ODS fact sheet). Since deficiency is linked with fatigue and lowered immunity, many experts recommend a steady, supplemental source for plant-based eaters.
• Magnesium: This mineral powers muscle function, bone health, sleep, and over 300 enzyme reactions. While magnesium is found in nuts, seeds, greens, and whole grains, studies indicate that soil depletion has reduced the amount present in many foods, and deficiency is increasingly common—even among those eating a healthy diet. Symptoms can include fatigue, muscle cramps, and restless sleep.

What about Protein and Creatine?

The concern around protein and plant-based eaters is nothing new. In fact, "but where do you get your protein" is the oldest vegan joke there is.

Creatine, on the other hand, is a relatively new topic in vegan nutrition, but it’s quickly gaining attention.

So let's quickly break down what you need to know about both—and whether you should consider supplementing with them.

Protein

What You Need to Know:

Most plant-based eaters can meet their protein requirements through whole foods. Eating a variety of beans, lentils, tofu, tempeh, whole grains, nuts, and seeds helps ensure you get all the essential amino acids you need. The myth of “incomplete proteins” has largely been debunked; variety throughout the day is what matters. For athletes, older adults, or anyone with higher needs, plant-based protein powders (like soy, pea, or rice) can help. Studies show these plant proteins are just as effective as animal-based options for muscle growth and recovery (Messina et al., 2019; Monteyne et al., 2020).

Not sure how much protein you need? Check out our calculator, here. 

Who Should Supplement:

• Active individuals, those building muscle, or adults over 60 may benefit from a plant-based protein supplement for convenience and to help meet daily targets.
• If you're struggling to get enough protein from whole foods, or variety is limited, a supplement can fill the gap.

Creatine

What You Need to Know:

Creatine supports quick energy production, muscle strength, and even brain function. Most dietary creatine comes from animal foods, which means vegans and vegetarians tend to have lower muscle creatine stores. While not essential for everyone, this can impact high-intensity sports, strength movements, or cognitive performance. Supplementing with vegan-friendly creatine monohydrate has been shown to increase both muscle and brain creatine for those not eating animal products (Brosnan & Brosnan, 2016; Bender & Mayhew, 2022).

Who Should Supplement:

• Vegans and vegetarians who are athletes, participate in high-intensity or strength sports, or want to support brain health as they age should consider creatine monohydrate.
• For the general plant-based eater, creatine isn’t essential, though it can offer extra benefits for performance or cognition, since you aren’t getting creatine from food. 

In short: protein and creatine supplements aren't "musts" for everyone following a plant-based diet, but both can add value depending on your activity level, health goals, and lifestyle. Making intentional choices to complement your plant-based diet with these nutrients ensures you’re covering all your bases… so you can thrive, not just get by.

The Problem with Traditional Vegan Multivitamins

Once you understand these nutrient gaps, the natural next step is to look for a supplement. But grabbing any bottle off the shelf can be counterproductive. Many standard multivitamins are designed for the general population and contain nutrients you already get in abundance from your plant-rich diet.

Taking high doses of nutrients you don’t need can be wasteful at best and potentially harmful at worst. You don’t need more Vitamin C or most B vitamins if you're eating whole plant foods. What you need is a targeted solution.

COMPLEMENT Essential, The Smarter Way to Supplement

After struggling to find a single product that provided only the essential nutrients for vegans—without the unnecessary extras—the team at COMPLEMENT created a solution.

COMPLEMENT Essential is not just another vegan multivitamin. It is a thoughtfully designed formula that provides the eight critical nutrients plant-based eaters need most, in their most effective and bioavailable forms. It's built to perfect your diet, not replace it.

Each dose delivers:

• Vitamin B12 for neurological health.
• Vitamin D3 sourced from vegan-friendly lichen.
• DHA/EPA derived directly from algae.
• Iodine, Zinc, and Vitamin K2 to cover common gaps.
• Selenium and Magnesium for antioxidant support and overall wellness.

With COMPELEMENT Essential, you can stop juggling multiple bottles and feel confident that your nutritional bases are covered. It’s the simple, evidence-based way to ensure your plant-based diet is working as hard for you as you are for it.

Take Control of Your Plant-Based Journey

You chose a plant-based lifestyle for your health, the planet, and the animals. Now, give your body the support it needs to truly flourish. Don't let common plant-based diet nutrient deficiencies hold you back from feeling your absolute best.

Imagine the peace of mind that comes with knowing you’re getting complete nutrition every day. Feel energized, sharp, and resilient, ready to take on whatever comes your way.

>> Click here to learn more about COMPLEMENT Essential and complete your plant-based diet.