Vegan Supplements, and do You Need Them for Weight Loss?

What supplements might you need to lose weight on a plant based diet?

While a whole-food, plant-based diet provides many essential nutrients, certain gaps can exist depending on your food choices, lifestyle, and weight loss goals. For vegans focusing on shedding extra pounds, deficiencies in key nutrients could potentially slow progress, affect energy levels, or even disrupt metabolic functions.

In this blog post, we’ll explore the role of supplements in a vegan weight loss journey. We’ll discuss which nutrients might be harder to obtain from diet alone, how they could impact your weight loss efforts, and whether supplements are necessary or just an added bonus. Whether you’re aiming to optimize your nutrient intake or simply curious about how to maintain balance while losing weight, this guide is intended to provide some background and information for you to then go and do your own research and speak to your health professionals for the best advice. Helping you to suss out your specific nutrient requirements is what I help all of my clients with – click here for a free health planning call with myself! I’ve based this post around key nutrients for vegans and then some key supplements that I see used most commonly online, this is just scratching the surface of the options out there. If you want advice or to chat about any other supplement I’ve not included here, send me a message on instagram or an email naturallyginanutrition@gmail.com I’d love to continue the conversation! 

*this post contains some affiliate links. Please know I would never ever promote a product i did not use myself or do not believe in fully.

B12

We can’t have a conversation about supplements for plant-based weight loss without talking about vitamiin B12. B12 is the only nutrient you can not get on a whole foods plant based diet. This is because it is made by microorganisms in the earth where our food grows. We wash and clean all our fruits and veggies (which is a good thing that means we get a lot less cholera & other bacterial illnesses now) but it does mean we get hardly any b12 if we’re solely eating plants. Lots of vegan alternatives are fortified with b12 like milks and meat alternatives but if you’re avoiding these foods, as many people do because you want a diet based on whole foods, then getting sufficient b12 can be tricky without a supplement. 

B12 is super important and is key for many functions including: 

• Red blood cell production 
• The nervous system 
• Energy metabolism 
• DNA synthesis
• B12 helps break down homocysteine, an amino acid that, in high levels, is associated with an increased risk of heart disease.

So you can easily see how a deficiency can be disastrous! Because b12 is stored in the liver, after going plant based, a deficiency can take years to develop which is why it’s important to have an appropriate supplementation strategy in place from the go. For this I recommend doing your own research or discussing the best options for you with a registered NT like myself to assess the appropriate dose and method of supplementation. 

So B12 is important for overall health, but what about weight loss? Although weight loss may not be helped by a b12 supplementation, a deficiency that causes low energy may hinder your progress, no one wants to work out or cook a nice healthy meal when they are exhausted. 

This is the one that I take. 

Vitamin D:

Vitamin D has long been investigated for impact on weight as obese people tend to have lower vitamin D status. But this meta-anlysis suggests that it may be that the excess body fat actually causes the low vitamin D levels and that levels do improve with weight loss (1).

Another meta-anlysis showed there is some evidence that vitamin D supplementation may support weight loss but more research is needed (2). 

However, sufficient vitamin D could influence the body’s ability to store and break down fat, and is involved in the production of leptin, a hormone that signals fullness to the brain. Low levels of vitamin D may interfere with leptin’s signaling, potentially leading to overeating. But none of this has been conclusively shown in the research. 

So while vitamin D deficiency may negatively impact weight management, supplementation alone is unlikely to lead to significant weight loss. Unless the supplement is correcting a deficiency and then improves your overall metabolic or hormonal health. This will be personal to everyone so testing your levels and working with a professional is again very important. 

For vegans Vitamin D can be difficult to obtain through diet alone especially if you live in a cold area where there is little sunlight or if you cover your skin. 

This is the one that I take

Fiber supplements: 

Fiber is one of my favorite nutrients—so underrated! For years, we didn’t fully appreciate its role, assuming it was useless because we can’t digest it. But now we know better: our gut microbes thrive on fiber, breaking it down and helping regulate our fullness and satiety hormones. Plus, fiber has zero calories, making it the perfect way to add volume to meals without increasing calorie intake—a winning combo for fat loss!

That said, I strongly recommend getting your fiber from whole plant foods. In their natural form, fiber comes packaged with a variety of nutrients that work together to boost overall health. Aim for at least 30g of fiber per day from diverse plant sources.

Interestingly, fiber supplements have also been shown to support weight loss, even without calorie restriction (7). If you’re curious and have the means, experimenting with a fiber supplement could provide an extra boost—not just for weight loss but also for nurturing a healthy gut microbiome. However, variety is key, so if you opt for supplements, rotate the types you use to keep your gut microbes happy. 

NOTE: yes there are minimal risks to a fiber supplement – so long as you also drink enough water – but some fiber supplements may impact the absorption of many medications. Also if you experience IBS especially in reaction to some high fiber foods it may be worth finding a low FODMAP one and going slowly. So again check with your GP or NT and if in doubt avoid taking alongside your medications. 

While supplements may seem like an appealing shortcut for weight loss, they should not be viewed as magic bullets. The science shows that certain supplements, such as fiber may provide small benefits when used appropriately and in conjunction with a balanced diet and active lifestyle. However, many popular products often lack sufficient evidence to support their effectiveness or come with potential downsides like digestive discomfort.

The most sustainable and effective approach to weight loss remains a nutrient-dense, whole-foods diet, regular physical activity, and consistent healthy habits. Supplements can play a supporting role, but they are just one piece of the puzzle. Before adding any supplement to your routine, it’s important to consult with a healthcare professional to ensure it aligns with your personal health goals and needs. Ultimately, building a strong foundation through food, movement, and mindfulness will yield the best long-term results for your weight loss and overall well-being.