Should I take any supplements as a vegetarian? A guide to key nutrients

December 11, 2025 •

5 min read

According to a 2021 review, vegetarians often have lower intake and status of vital nutrients like Vitamin B12, Vitamin D, iron, and zinc compared to meat-eaters. This raises a critical question for many following a plant-based diet: should I take any supplements as a vegetarian to fill these potential gaps? While a well-planned diet is the foundation, strategic supplementation can be a smart strategy.

Quick Summary

Depending on their specific diet and overall health, vegetarians may need to supplement for nutrients often found primarily in animal products, including B12, iron, and omega-3s. Monitoring your diet and consulting a healthcare provider can help determine individual needs.

Key Points

Mandatory B12: All vegans and many vegetarians need Vitamin B12 supplements or reliable fortified foods, as it's almost exclusively from animal sources.
Focus on Bioavailability: Plant-based iron and zinc (non-heme) are less absorbed than animal sources, requiring attention to food pairing (with Vitamin C) and preparation methods.
Consider Omega-3s: Supplementing with algae-based EPA and DHA is a reliable way to get these essential fatty acids, as the body's conversion from plant sources is inefficient.
Mindful Calcium and D: While plant sources exist, checking fortified food labels and considering supplements for both calcium and Vitamin D is wise, especially with low sun exposure.
Personalized Plans: The necessity for supplementation depends on the specific type of vegetarian diet, food choices, life stage, and individual health needs. Blood tests can offer clarity.

Understanding Nutrient Gaps in a Vegetarian Diet

While a vegetarian diet offers numerous health benefits, excluding meat means certain nutrients require more careful consideration. Some are less bioavailable from plant sources, while others are simply absent from plants and must be obtained from dairy, eggs, or fortified foods. Understanding these potential gaps is the first step toward making an informed decision about supplementation.

Vitamin B12: An Essential for All Vegans and Many Vegetarians

Vitamin B12 is arguably the most critical supplement for those on a strict plant-based diet, as it is found almost exclusively in animal products like eggs and dairy. It is crucial for red blood cell formation, brain function, and nerve health. While lacto-ovo vegetarians get some B12 from dairy and eggs, intake can still be low, especially if consumption is infrequent. For vegans, supplementation is mandatory to prevent deficiency, which can cause severe neurological issues.

Fortified foods: Good for daily intake. Examples include fortified cereals, nutritional yeast, and plant milks.
Supplements: Recommended for consistent, reliable dosing. Regular testing can help monitor levels.

Iron: Non-Heme Sources Require a Boost

Vegetarians can meet their iron needs with plant-based foods, but the non-heme iron found in plants is less easily absorbed by the body than the heme iron from meat. This can put some vegetarians, particularly menstruating women, at a higher risk of deficiency.

Enhancing absorption: Pairing iron-rich plant foods with Vitamin C dramatically increases absorption. For example, adding lemon juice to a spinach salad or bell peppers to lentils.
Supplementation: An iron supplement may be necessary for those with a confirmed deficiency. Formulations like ferrous bisglycinate chelate are often easier on the stomach.

Omega-3 Fatty Acids: Algae-Based is Best

Omega-3 fatty acids, particularly EPA and DHA, are vital for brain and heart health. While plant sources like flaxseeds, walnuts, and chia seeds contain ALA (a precursor), the body's conversion to EPA and DHA is inefficient. Therefore, many vegetarians can benefit from direct supplementation.

Algae oil: Algae-based supplements provide a direct source of EPA and DHA, bypassing the inefficient conversion process.
Dietary sources: Including flaxseeds, walnuts, and chia seeds in your diet still offers valuable ALA.

Vitamin D: The "Sunshine Vitamin"

Vitamin D is essential for calcium absorption and bone health. Sources include fortified foods and sunlight exposure, but deficiency is common regardless of diet, and some animal-based sources (like D3 from lanolin) are not vegetarian-friendly.

Supplementation: D2 (ergocalciferol) from fungi or vegan D3 from lichen are suitable options.
Fortified foods: Look for fortified plant milks and cereals.

Calcium: More Than Just Dairy

While dairy is a primary source for many, vegetarians can obtain sufficient calcium from plant sources and fortified foods. However, some plant compounds like oxalates (in spinach) can inhibit absorption.

High-bioavailability sources: Good choices include kale, bok choy, and collard greens.
Supplements: Calcium supplements can fill dietary gaps, but care should be taken not to overdo it, as excessive intake can cause issues like kidney stones.

Zinc: Bioavailability Matters

Zinc supports immune function, wound healing, and enzyme activity. Like iron, the bioavailability of zinc from plant sources is lower due to phytates in legumes, nuts, and grains.

Preparation: Soaking and sprouting can help reduce phytate levels in some foods.
Supplements: Zinc supplementation can be beneficial, especially for those with low levels. It may be wise to supplement with copper as well, as high zinc intake can affect copper absorption.

Comparison of Vegetarian Diets and Supplementation Needs


Nutrient	Lacto-ovo Vegetarian	Ovo-Vegetarian	Lacto-Vegetarian	Vegan	Supplement Often Needed?
Vitamin B12	May be low if intake of eggs/dairy is inconsistent.	Requires consistent sourcing from fortified foods and/or supplements.	Requires consistent sourcing from fortified foods and/or supplements.	Yes, mandatory.	Yes, especially for vegans and those with low intake of dairy/eggs.
Iron	Non-heme iron from plants may be less absorbed. Eggs provide some.	Less absorbed non-heme iron. Eggs provide some.	Less absorbed non-heme iron. Dairy provides very little.	Most relies on less-absorbed non-heme iron.	Potentially, especially for individuals at higher risk.
Calcium	Found in dairy and certain vegetables.	Requires focusing on fortified foods and low-oxalate greens.	Found in dairy products.	Requires diligent intake from fortified foods and greens.	Potentially, especially for vegans or those with low dairy/egg intake.
Vitamin D	Sources include fortified foods, sun exposure, and eggs.	Sources include fortified foods and sun exposure.	Sources include fortified foods and sun exposure.	Limited food sources, must rely on sun or fortified options.	Yes, common for most people, especially in low-sun regions.
Omega-3s	ALA from plants, some EPA/DHA from eggs. Inefficient conversion.	ALA from plants, some EPA/DHA from eggs. Inefficient conversion.	ALA from plants only. Inefficient conversion.	ALA from plants only. Inefficient conversion.	Algae-based supplements recommended for EPA/DHA intake.
Zinc	Plant sources have lower bioavailability due to phytates.	Plant sources have lower bioavailability due to phytates.	Plant sources have lower bioavailability due to phytates.	Plant sources have lower bioavailability due to phytates.	Potentially, as plant-based zinc is less bioavailable.

Making an Informed Decision

Before starting any supplement regimen, the first step is to assess your current diet. Are you consistently incorporating fortified foods and reliable nutrient sources? Are you an athlete, pregnant, or over 50 with increased nutritional needs? A blood test can provide definitive information on your current nutrient levels. Consulting a registered dietitian can offer personalized advice and help create a plan that meets your needs with or without supplements. The goal is a balanced diet, with supplements serving as an insurance policy to fill proven nutritional gaps.

Conclusion: A Proactive Approach to Health

For many, the question of whether to take supplements as a vegetarian is not about a fundamental flaw in the diet but about ensuring optimal nutrient intake. While a balanced and diverse vegetarian diet is rich in many essential vitamins, minerals, and antioxidants, specific nutrients like Vitamin B12, iron, and omega-3s often require proactive management. This might involve carefully selecting fortified foods, mastering food pairing for better absorption, or adding quality, vegetarian-friendly supplements. The key is to be mindful of your nutritional needs and use the right tools, including supplementation when necessary, to maintain excellent health on your plant-based journey.

Visit the Academy of Nutrition and Dietetics for more information on vegetarian eating.

Frequently Asked Questions

Not necessarily, but you should monitor your diet closely. Lacto-ovo vegetarians, who eat dairy and eggs, have sources of Vitamin B12 and calcium. However, if your intake of these foods is low or inconsistent, or if you are at a high-risk life stage like pregnancy, supplementation might be beneficial.

For those consuming no animal products (vegans) or minimal dairy/eggs, the most crucial supplements are Vitamin B12, an algae-based omega-3 (for EPA/DHA), and potentially Vitamin D. Iron, calcium, and zinc are also common considerations depending on dietary intake.

It is possible to get enough iron from plant sources, but it requires careful planning. Since non-heme iron from plants is less absorbed, pairing iron-rich foods like lentils and spinach with a Vitamin C source, such as lemon juice, is essential to increase absorption.

Signs can vary. B12 deficiency might manifest as fatigue, weakness, or neurological issues. Iron deficiency (anemia) can cause tiredness and shortness of breath. Low Vitamin D can lead to bone pain and muscle weakness.

Vegetarians should be mindful that Vitamin D3 is often sourced from animal products (lanolin). Vegan-friendly Vitamin D2 (ergocalciferol) from fungi or vegan D3 from lichen are suitable alternatives.

Yes, getting a blood test is a wise and recommended step before starting a supplement regimen. It provides definitive information on your current nutrient levels and helps tailor supplementation to your specific needs.

A multivitamin can act as a safety net to cover baseline needs, especially if it's formulated for plant-based diets. However, it is not a replacement for addressing specific, higher-risk deficiencies like B12 or iron, which may require targeted, higher-dose supplements.