What nutrients do vegans not get?

According to a 2021 systematic review, vegan diets often result in lower intake of several key micronutrients, including vitamin B12, vitamin D, iodine, and zinc. While a plant-based diet can be incredibly healthy, careful planning is required to ensure no nutritional gaps emerge over time.

Quick Summary

This article outlines essential nutrients a vegan diet may lack, such as B12, iron, and calcium, detailing why deficiencies occur and how to ensure adequate intake through diet, fortified foods, and supplements.

Key Points

• Vitamin B12: Supplementation is essential as plant foods do not reliably provide this nutrient, which is vital for nerve health and red blood cells.

• Iron Bioavailability: Non-heme iron from plants is less absorbed; enhance intake by pairing with Vitamin C and avoiding tea and coffee with meals.

• Calcium Sources: Focus on fortified plant milks and tofu, and low-oxalate greens like kale to ensure adequate calcium for bone health.

• Vitamin D Reliance: Vegans often have lower vitamin D levels; use fortified foods, safe sun exposure, or a vegan D3 supplement.

• Omega-3s (EPA/DHA): While ALA is found in flax and walnuts, use an algal oil supplement for reliable EPA and DHA intake.

• Iodine Consideration: Use iodized salt or small amounts of seaweed, or consider a supplement, as iodine content in plant foods is variable.

• Zinc Absorption: Maximize zinc absorption from plant sources like legumes and nuts by soaking, sprouting, or fermenting.

• Holistic Approach: Successful vegan nutrition relies on a combination of intentional food choices, fortified products, and strategic supplementation to cover all bases.

Common Nutrient Deficiencies in Vegan Diets

While a well-planned vegan diet is a healthy choice for many, several key nutrients naturally abundant in animal products require special attention. The following sections delve into the most common deficiencies and strategies for maintaining a balanced intake.

Vitamin B12: A Critical Nutrient for Vegans

Vitamin B12, or cobalamin, is crucial for nerve function, red blood cell production, and DNA synthesis. It is synthesized by microorganisms, not by animals, but accumulates primarily in animal products. Plant-based foods are unreliable sources, making supplementation essential for all vegans. B12 deficiency can lead to serious health problems, including megaloblastic anemia and neurological damage. The Vegan Society and other health bodies strongly advise regular B12 supplementation.

To ensure adequate B12 intake:

• Supplements: The most reliable method.
• Fortified Foods: Regularly consume foods fortified with B12, such as nutritional yeast, plant-based milks, and breakfast cereals.
• Testing: Periodic blood tests can help monitor B12 status.

Iron: The Importance of Bioavailability

Although many plant-based foods contain iron, the non-heme iron found in plants is less bioavailable and absorbed less efficiently than the heme iron from animal products. Vegan adults often have lower iron stores, although clinical anemia is less common.

To maximize iron absorption:

• Pair with Vitamin C: Consume iron-rich foods with sources of vitamin C (e.g., citrus fruits, bell peppers, broccoli) to significantly increase absorption.
• Avoid Inhibitors: Limit tea and coffee consumption around meals, as their tannins can inhibit iron absorption.
• Iron-Rich Foods: Focus on legumes, whole grains, nuts, and dark leafy greens.

Calcium: Building Strong Bones Without Dairy

Dairy products are a primary source of calcium in many diets, so vegans must be intentional about their intake. Research indicates that vegans often have lower calcium intake and, potentially, lower bone mineral density. Certain compounds in plants, like oxalates and phytates, can also reduce calcium absorption.

Excellent vegan calcium sources include:

• Fortified Foods: Calcium-fortified plant milks, tofu set with calcium salts, and orange juice are excellent options.
• Low-Oxalate Greens: Kale, bok choy, and broccoli offer calcium with high bioavailability.
• Other Sources: Beans, pulses, almonds, and figs also contribute.

Vitamin D: The Sunshine Vitamin

Vitamin D is crucial for calcium absorption and bone health. While primarily synthesized via sun exposure, dietary sources are important, especially for those in northern climates or with darker skin. The richest natural food sources are animal-based. Vegans may have lower circulating levels of vitamin D.

Vegan-friendly vitamin D sources:

• Sunlight: Safe, limited sun exposure is one source, though it depends on many factors.
• Fortified Foods: Many plant milks and cereals are fortified with vitamin D.
• Supplements: Vegan D3 from lichen is an effective option, as some studies suggest it is more potent than D2.
• UV-Treated Mushrooms: Mushrooms exposed to UV light can contain high levels of D2.

Iodine: Essential for Thyroid Health

Iodine is vital for healthy thyroid function, but plant-based diets can be low in this mineral. Many plant foods' iodine content depends on the soil, which is often depleted. Dairy products are often cited as a source because of processing methods and fortified feed, not because of inherent iodine.

To get enough iodine:

• Iodized Salt: A simple and reliable option for many.
• Seaweed: Nori, kelp, and wakame are excellent sources, but intake should be regulated to avoid overconsumption.
• Supplements: A multivitamin with iodine can be a good safety net.

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

While vegans can get ALA (alpha-linolenic acid) from sources like flaxseed and walnuts, the conversion to the more biologically active EPA and DHA is inefficient. EPA and DHA are typically found in fatty fish, but originate in marine algae.

Vegan omega-3 sources:

• ALA Sources: Ground flaxseed, chia seeds, hemp seeds, and walnuts are rich in ALA.
• Algal Oil Supplements: These provide a direct, reliable source of EPA and DHA.

Zinc: Bioavailability is Key

Zinc is important for immune function and wound healing, but its bioavailability can be lower in plant foods due to phytic acid. However, a well-planned vegan diet can provide sufficient zinc.

Tips for maximizing zinc intake:

• Cooking Methods: Soaking, sprouting, and fermenting legumes and grains can reduce phytate levels.
• Protein-Rich Foods: Combine plant proteins with zinc sources to improve absorption.
• Zinc-Rich Foods: Legumes, seeds, nuts, and whole grains are good sources.

Comparison of Key Nutrients for Vegans and Omnivores

This table summarizes the typical challenges and solutions for obtaining critical nutrients on a vegan diet versus a standard omnivorous diet.

Nutrient	Primary Vegan Challenge	Typical Omnivore Source	Vegan Strategies for Adequacy
Vitamin B12	Not reliably available in unfortified plant foods.	Meat, fish, eggs, and dairy.	Supplementation, fortified nutritional yeast and plant milks.
Iron	Non-heme iron is less bioavailable.	Heme iron from meat and fish.	Vitamin C pairing, rich plant sources (legumes, greens).
Calcium	Excluding dairy requires diligent sourcing.	Dairy products (milk, cheese, yogurt).	Fortified plant milks, calcium-set tofu, low-oxalate greens.
Vitamin D	Limited natural dietary sources; depends on sun.	Fatty fish, eggs, fortified dairy.	Sunlight, fortified foods, vegan D3 supplements.
Iodine	Content in plant foods is variable and often low.	Dairy, fish, and iodized salt.	Iodized salt, seaweed (in moderation), supplements.
Omega-3s (EPA/DHA)	Inefficient conversion from plant-based ALA.	Fatty fish and fish oil.	Algal oil supplements, ALA-rich foods (flaxseed, walnuts).
Zinc	Lower bioavailability due to phytates.	Meat, fish, and dairy.	Legumes, nuts, seeds, soaking/sprouting to reduce phytates.

Conclusion

A vegan diet can be perfectly healthy and nutritionally complete, but it demands careful planning to ensure adequate intake of certain nutrients that are more easily obtained from animal products. Key areas for focus include vitamin B12, iron, calcium, vitamin D, iodine, omega-3 fatty acids, and zinc. By incorporating fortified foods, prioritizing nutrient-dense plant sources, employing smart preparation techniques, and using supplements where necessary, vegans can easily meet their dietary needs. Regularly monitoring your nutrient levels, especially B12, with your healthcare provider is a proactive step toward long-term wellness. Education and awareness are the most powerful tools for thriving on a plant-based diet.

For more in-depth nutritional guidance on vegan diets, you can consult authoritative resources such as the National Institutes of Health.

Frequently Asked Questions

Can vegans get enough vitamin B12 without supplements?

No, reliable sources of vitamin B12 are not found in unfortified plant foods. Regular supplementation or consistent consumption of B12-fortified foods is essential for all vegans to prevent deficiency.

What is the best way for a vegan to ensure they get enough iron?

Combine iron-rich plant foods like lentils and greens with vitamin C sources, such as bell peppers or citrus fruits, at the same meal to maximize absorption. Avoid drinking coffee or tea around mealtimes.

Do all vegans need to take a calcium supplement?

Not necessarily. Many can meet their needs through fortified plant milks, calcium-set tofu, and low-oxalate leafy greens. However, if intake is low, a supplement may be beneficial, particularly for those with a higher fracture risk.

How can a vegan get enough vitamin D if they don't get much sun?

Without sufficient sun exposure, vegans can rely on vitamin D-fortified foods like plant milks and cereals, UV-treated mushrooms, or a vegan vitamin D3 supplement from lichen.

What are the best vegan sources of omega-3 fatty acids?

For ALA, good sources include ground flaxseed, chia seeds, and walnuts. For the more bioavailable EPA and DHA, an algal oil supplement is the most reliable vegan source.

Is zinc absorption a problem for vegans?

Zinc absorption can be lower in plant foods due to phytates. However, a varied diet with legumes, nuts, and seeds can provide enough zinc. Soaking, sprouting, or fermenting can also improve absorption.

Is seaweed a safe source of iodine for vegans?

Yes, seaweed is an excellent source, but iodine content can vary dramatically. It's best to use it sparingly and consistently rather than relying on large, infrequent portions to avoid excessive intake.