Navigating Nutrient Gaps: What Will Vegans Be Deficient In?

According to a 2021 systematic review, vegans consistently have lower intake and status of several key nutrients compared to omnivores. This raises the critical question of what will vegans be deficient in if they do not plan their diet carefully and how to supplement effectively.

Quick Summary

A well-planned vegan diet is essential to avoid potential nutritional deficiencies. Key areas of concern include vitamin B12, iron, calcium, vitamin D, omega-3 fatty acids, and iodine. Conscious food choices, fortified products, and supplementation are crucial for bridging these gaps and maintaining optimal health on a vegan diet.

Key Points

• Vitamin B12: Vegans must obtain B12 from fortified foods or supplements, as it is not reliably found in plant sources.

• Iron: The body absorbs non-heme iron from plants less efficiently, so pairing with vitamin C is essential to boost absorption.

• Calcium: Calcium-set tofu, fortified plant milks, and specific leafy greens are critical for bone health, alongside vitamin D for absorption.

• Vitamin D: Exposure to sunlight and supplementation are the most reliable sources, as fortified vegan foods alone are often insufficient.

• Omega-3s: Since the conversion of plant-based ALA to EPA and DHA is low, a microalgae supplement is the best way to get preformed omega-3s.

• Iodine and Zinc: Trace minerals like iodine (from iodized salt or seaweed) and zinc (from legumes and seeds) require attention to ensure sufficient intake.

Common Nutritional Concerns in Vegan Diets

While a well-planned vegan diet can offer numerous health benefits, excluding all animal products presents a unique set of nutritional challenges. Certain vitamins and minerals are primarily found in animal products or are absorbed less efficiently from plant sources. Addressing these potential deficiencies requires strategic dietary planning, an understanding of plant-based sources, and often, supplementation.

Vitamin B12: The Most Critical Supplement

Vitamin B12 is arguably the most critical nutrient for vegans to monitor, as it is not reliably available in unfortified plant foods. A deficiency can lead to serious health issues, including megaloblastic anemia and irreversible nervous system damage. The only dependable vegan sources are fortified foods and supplements.

• Fortified foods: Many breakfast cereals, nutritional yeast, and plant milks are fortified with B12. Vegans should check labels to ensure they consume enough fortified products daily.
• Supplements: The Vegan Society recommends either a daily supplement of at least 10 micrograms or a weekly supplement of 2000 micrograms to ensure adequate intake.

Iron: The Importance of Pairing and Bioavailability

Iron is necessary for producing red blood cells and carrying oxygen throughout the body. While many plant foods contain iron, it is in a form called non-heme iron, which is less readily absorbed by the body than the heme iron found in meat.

• Increase absorption: Pairing iron-rich plant foods with sources of vitamin C, such as citrus fruits or bell peppers, significantly boosts non-heme iron absorption.
• Good sources: Excellent plant-based iron sources include lentils, chickpeas, tofu, dark leafy greens (like spinach and kale), and fortified cereals.
• Inhibitors: It is also advisable to avoid consuming coffee and tea within an hour of an iron-rich meal, as they can inhibit absorption.

Calcium: Building Strong Bones Without Dairy

Calcium is vital for maintaining healthy bones and teeth. With dairy products off the table, vegans must actively seek out other sources to meet their daily requirements.

• Fortified alternatives: Many plant milks and yogurts are fortified with calcium. Calcium-set tofu is another excellent option.
• Leafy greens: Certain leafy greens, such as kale and broccoli, are good sources, though others like spinach contain oxalates that inhibit absorption.
• Other sources: Nuts like almonds, seeds like tahini and sesame, and dried figs are also viable sources.

Vitamin D: The Sunshine Vitamin Dilemma

Vitamin D aids in calcium absorption and bone health, but natural food sources are limited, even for omnivores. For vegans, the primary dietary sources are fortified foods and supplements.

• Sunshine: Regular, moderate sun exposure is a natural way for the body to produce vitamin D.
• Fortified options: Look for fortified cereals, plant milks, and fortified margarines.
• Mushrooms: Some mushrooms, when exposed to ultraviolet light, can be a good source of vitamin D.
• Supplementation: A supplement is often recommended, especially during winter months when sun exposure is limited. Vegan-friendly vitamin D3 from lichen is available.

Omega-3 Fatty Acids: ALA, EPA, and DHA

The three main types of omega-3s are ALA, EPA, and DHA. While plant foods provide ALA, the body's conversion rate to the more potent EPA and DHA is very low.

• ALA sources: Walnuts, flaxseeds, chia seeds, and hempseeds are excellent sources of ALA.
• EPA and DHA sources: A microalgae supplement is the most reliable vegan source for preformed EPA and DHA.

Iodine and Zinc: Trace Minerals to Consider

Iodine is essential for thyroid function, while zinc supports the immune system. Vegan diets may sometimes be low in these trace minerals.

• Iodine: Iodized salt and seaweed (like nori) are reliable sources.
• Zinc: Good plant sources include legumes, nuts, seeds, and whole grains. Soaking beans and grains can improve zinc absorption.

Comparison of Vegan vs. Omnivore Diet for Key Nutrients

Nutrient	Vegan Diet Sources	Omnivore Diet Sources	Vegan Absorption/Status	Omnivore Absorption/Status
Vitamin B12	Fortified foods, supplements	Meat, fish, dairy, eggs	Only reliable via fortification/supplementation	Naturally occurring; generally adequate intake
Iron	Legumes, leafy greens, fortified cereals	Red meat, poultry, fish	Non-heme iron, lower bioavailability; requires pairing with vitamin C	Heme iron, higher bioavailability
Calcium	Fortified plant milks/yogurts, calcium-set tofu, kale	Dairy products (milk, cheese, yogurt)	Good sources available, but some plants contain inhibitors; need strategic planning	Generally high intake from dairy
Vitamin D	Sunlight, fortified foods, lichen-based supplements	Oily fish, eggs, fortified dairy	Dependent on sun exposure and fortified products; supplementation often necessary	Some dietary sources, but sun exposure and fortification are also key
Omega-3s	ALA from flaxseeds, walnuts; preformed EPA/DHA from microalgae supplements	Oily fish and seafood	Lower EPA and DHA status due to poor ALA conversion; microalgae supplementation is key	Directly consumes EPA and DHA

Conclusion: Strategic Planning Is Key

A vegan diet can be perfectly healthy and nutritionally complete with careful planning. While animal products provide certain nutrients more readily, plant-based equivalents, fortified foods, and targeted supplementation can fill any potential nutritional gaps. Vegans should prioritize a regular, reliable source of vitamin B12, focus on enhancing iron and calcium absorption, and consider supplementation for vitamin D and omega-3s (EPA/DHA), especially during winter or for pregnant/breastfeeding individuals. By being mindful of these key nutrients, vegans can enjoy the benefits of a plant-based lifestyle without compromising their health.

Vegan Resource: The Vegan Society

For more in-depth nutritional guidance, including detailed information on Vitamin B12 and Omega-3s, visit The Vegan Society's nutrition and health section. They provide evidence-based recommendations to help vegans plan a healthy and balanced diet.

The Vegan Society

Frequently Asked Questions

What is the most common deficiency for vegans?

Vitamin B12 is the most critical and common deficiency risk for vegans because it is not reliably found in plant foods. Adequate intake requires consuming fortified foods or supplements.

How do vegans get enough iron?

Vegans can get iron from plant sources like lentils, chickpeas, and leafy greens. To maximize absorption, they should pair these foods with vitamin C-rich foods and avoid drinking coffee or tea around mealtimes.

Do vegans need to take supplements?

Yes, supplementation is necessary for a well-planned vegan diet. A reliable source of vitamin B12 is essential, and supplements for vitamin D, iodine, and omega-3 (EPA/DHA) are often recommended.

Can vegans get omega-3 from plant foods?

Vegans can get ALA omega-3s from foods like flaxseeds, chia seeds, and walnuts. However, for adequate levels of EPA and DHA, a microalgae supplement is the most effective source.

What are the best vegan calcium sources?

The best vegan calcium sources include calcium-fortified plant milks and yogurts, calcium-set tofu, kale, almonds, and tahini. It's important to consume vitamin D alongside these foods for proper absorption.

How can vegans get vitamin D?

Vegans can get vitamin D from direct sunlight exposure, fortified plant milks and cereals, UV-grown mushrooms, and vegan supplements derived from lichen.

Are fortified foods enough to prevent vegan deficiencies?

While fortified foods are a valuable source, they are not always sufficient on their own, especially for vitamins like B12 and D. Targeted supplementation is often a more reliable approach to prevent deficiencies.