How to Increase Vitamin B12 and Vitamin D for Vegetarians

November 14, 2025 •

4 min read

According to research, vegetarians and vegans are at higher risk for vitamin B12 deficiency since the nutrient is primarily found in animal products. Finding reliable non-animal sources is crucial, just as it is for vitamin D, often known as the 'sunshine vitamin.' This guide explains how to increase vitamin B12 and vitamin D for vegetarians through diet, sunlight, and supplementation.

Quick Summary

This guide provides practical strategies for vegetarians to boost their intake of vitamins B12 and D. It focuses on incorporating fortified foods, leveraging sun exposure, and identifying reliable vegetarian-friendly supplements to prevent deficiency and support overall health.

Key Points

Fortified Foods are Key: Since B12 and D are limited in natural plant sources, regularly consume fortified foods like nutritional yeast, plant-based milks, and cereals.
Leverage Sun Exposure: Strategic, moderate sun exposure is a vital and natural way for vegetarians to increase their vitamin D levels.
Mushrooms are a Natural Source: Select mushrooms that have been exposed to UV light, or do it yourself, to boost their vitamin D content.
Supplementation is a Reliable Backup: For consistent and optimal intake, especially for those with low levels or limited sun, supplements are an effective strategy.
A Combined Approach is Best: The most successful approach involves combining fortified foods, sun exposure, and targeted supplements to cover all bases.
Consult a Professional: Speak with a healthcare provider or dietitian to determine your specific needs and create a personalized plan to avoid deficiencies.

The Importance of Vitamins B12 and D

Understanding the vital roles of these nutrients highlights why vegetarians must be proactive about their intake. Vitamin B12 is essential for red blood cell formation, DNA synthesis, and maintaining a healthy nervous system. A deficiency can lead to fatigue, memory issues, and permanent neurological damage. Vitamin D, while produced by the body through sun exposure, is critical for calcium absorption, bone health, and immune system function. Insufficient levels can lead to weakened bones, poor immune response, and low mood.

Vegetarian Sources of Vitamin B12

Since vitamin B12 is not naturally present in most plant foods, vegetarians must rely on other sources. For ovo-lacto vegetarians, dairy and eggs are the mainstays, but fortified products are essential for all vegetarians.

Fortified Foods

Nutritional Yeast: A deactivated yeast product with a cheesy, nutty flavor. A single tablespoon of fully fortified nutritional yeast can provide 100% of the daily value for vitamin B12. It can be sprinkled on pasta, popcorn, or salads.
Fortified Breakfast Cereals: Many whole-grain cereals are enriched with B12, offering a simple way to start your day with a boost. Always check the nutrition label for fortification.
Fortified Plant-Based Milks: Soy, almond, and oat milks are often fortified with vitamin B12. A single cup of fortified soy milk can provide a significant portion of the daily requirement.
Certain Meat Alternatives: Some vegetarian and vegan products, such as veggie burgers or plant-based meats, are fortified with B12.

Lacto-Ovo Vegetarian Options

Dairy Products: Milk, yogurt, and cheese are good sources of vitamin B12 for vegetarians who consume dairy. Studies suggest the B12 from dairy is absorbed quite efficiently.
Eggs: The vitamin B12 in eggs is concentrated in the yolk and is more bioavailable than the B12 in egg whites. Eating the whole egg is recommended.

Vegetarian Sources of Vitamin D

While sunlight is a primary source, dietary options are limited for vegetarians. Combining food, sun, and supplements is the most effective approach.

Natural and Fortified Food Sources

Mushrooms: Some mushrooms, especially those exposed to UV light, are natural sources of vitamin D2. Leaving mushrooms like portobello or shiitake in the sun for 30-60 minutes before cooking can significantly increase their vitamin D content.
Fortified Dairy and Plant Milks: Many brands of cow's milk and plant-based milks like soy, almond, and oat milk are fortified with vitamin D.
Fortified Orange Juice: Certain brands of orange juice are fortified with vitamin D and calcium.
Egg Yolks: For ovo-vegetarians, eggs are a decent source of vitamin D, especially if the chickens were raised with sun exposure.

Strategic Sun Exposure

For many, sunlight is the most significant source of vitamin D. Regular, moderate sun exposure can help maintain adequate levels. Aim for 10-30 minutes of midday sun exposure several times a week, depending on your location, skin type, and the time of year. Those living in regions with limited winter sunlight or who have darker skin may need more sun time or rely more heavily on fortified foods and supplements.

Supplementation for Optimal Levels

For many vegetarians, especially those with minimal sun exposure, supplements are a necessary and reliable way to ensure sufficient intake.

Vitamin B12 Supplements: The most common forms are cyanocobalamin and methylcobalamin. Cyanocobalamin is the most stable and well-researched form, while methylcobalamin is also effective. B12 supplements are widely available as oral tablets, sublinguals, and sprays.
Vitamin D Supplements: Vegetarians can choose between vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) supplements. Vitamin D2 is plant-based, made from yeast or fungi, and suitable for all vegetarians. While D3 is often animal-derived, vegan D3 from lichen is also available and is generally considered more effective at raising blood levels.

Supplementation vs. Fortified Foods: A Comparison


Feature	Fortified Foods	Supplements
Convenience	Integrated into daily meals; no extra steps needed.	Requires a separate pill, capsule, or spray.
Absorption	Variable, as absorption can be affected by other food components and intrinsic factors.	Can provide a reliable, concentrated dose for efficient absorption.
Dosage	The amount per serving is often lower and may require multiple servings daily to meet requirements.	Dosage is precise and higher concentrations are available, which is useful for correcting deficiencies.
Source Reliability	Must check labels diligently, as not all products are fortified or contain sufficient amounts.	Consistent and reliable, particularly with third-party tested brands.
Cost	Typically more affordable per dose, as fortification adds minimal cost to the product.	Higher initial cost, but can be more cost-effective for meeting specific, higher dose needs.

A Combined Approach for Optimal Health

A robust strategy for vegetarians involves a multi-pronged approach combining diet, sun, and supplementation. For example, starting the day with fortified cereal and plant-based milk ensures a baseline B12 and D intake. Complement this with moderate, safe sun exposure during the day. Incorporate nutritional yeast into dishes like soups or sauces for an extra boost. For those at higher risk of deficiency, especially those who avoid dairy and eggs, or have limited sun, a reliable supplement is a crucial safety net.

Remember to consult with a healthcare provider or a registered dietitian to determine your specific needs and create a personalized plan. They can help monitor your levels and recommend the right dosage if supplementation is needed. For more detailed nutritional guidance, consider visiting the Dietitians Australia website.

Conclusion

Navigating a vegetarian diet requires careful attention to specific nutrients like vitamins B12 and D, which are scarce in plant-based sources. By consistently incorporating fortified foods such as nutritional yeast, fortified cereals, and plant-based milks, along with strategic sun exposure, vegetarians can maintain healthy levels. For many, supplementation offers a reliable and convenient method to ensure sufficient intake and prevent deficiency. A combination of these strategies, tailored to individual needs, is the best path to optimal health and well-being.

Frequently Asked Questions

It can be challenging for vegetarians to obtain sufficient levels of both vitamins from diet alone, especially B12, which is primarily found in animal products. Relying on fortified foods and supplements is often necessary for optimal intake.

No, only mushrooms that have been grown or exposed to UV light contain significant amounts of vitamin D2. Most commercially grown mushrooms that are kept in the dark have low levels unless specifically labeled as 'UV-exposed'.

The amount varies based on skin type, location, and season. A general guideline is 10–30 minutes of midday sun exposure a few times per week. Darker skin tones require longer exposure times to produce the same amount of vitamin D.

Cyanocobalamin is a well-researched, stable, and widely available form of B12 suitable for vegetarians. Methylcobalamin is another effective option.

No, traditional vitamin D3 (cholecalciferol) is often sourced from animal products like sheep's wool lanolin. However, vegan D3 derived from lichen is available, and vitamin D2 (ergocalciferol) is always plant-based and suitable for vegetarians.

Symptoms can include extreme tiredness, lack of energy, pins and needles, a sore tongue, and memory problems. If left untreated, more severe neurological symptoms can develop.

Common symptoms include fatigue, bone pain, muscle weakness, and a compromised immune system. Low levels can also be linked to mood imbalances, such as depression.