Understanding a Nutrition Diet: Which vitamins are obtained from plants?

October 30, 2025 •

4 min read

According to the Academy of Nutrition and Dietetics, a well-planned, plant-based diet can provide a wide range of essential nutrients, including many vitamins. For those following this eating pattern, understanding which vitamins are obtained from plants and which may require extra attention is key for optimal health.

Quick Summary

A plant-focused diet is rich in most essential vitamins, including A, C, E, K, and several B vitamins found in fruits, vegetables, and legumes. Nutrients like B12 and D often require fortification or supplementation to meet dietary needs, while a varied diet maximizes absorption of plant-derived nutrients.

Key Points

Rich in Provitamin A: Carrots, sweet potatoes, and leafy greens are excellent sources of beta-carotene, converted to vitamin A.
High in Vitamin C: Citrus fruits, bell peppers, broccoli, and kiwi are loaded with this antioxidant, but it is sensitive to heat.
Source of Vitamin E: Found in plant oils, nuts, seeds, and leafy greens, vitamin E acts as a key antioxidant.
Supplies Vitamin K1: Green leafy vegetables like kale and spinach are potent sources of vitamin K1.
Abundant in B Vitamins: Most B-complex vitamins (B1, B2, B3, B5, B6, B7, B9) are readily available in whole grains, nuts, seeds, and legumes.
B12 Requires Fortification: Vitamin B12 is not naturally present in plants and must be obtained from fortified foods or supplements in a vegan diet.
Enhance Absorption with Fat: Pair fat-soluble vitamins (A, E, K) from plant foods with a source of healthy fat for better absorption.

Plant-Powered Vitamins: The Essential Nutrient Guide

For those following a diet centered on plant foods, understanding the source of essential vitamins is crucial. The plant kingdom offers a powerful array of fat-soluble and water-soluble vitamins, though a few require specific consideration or supplementation to ensure adequate intake.

Vitamins You Can Easily Obtain from Plants

Plants are a primary source for many vitamins, supplying them in forms that are easily integrated into a healthy diet. A varied consumption of fruits, vegetables, nuts, seeds, and grains can provide a robust nutritional foundation.

Provitamin A (Carotenoids)

Plants are rich in provitamin A carotenoids, which the human body converts into vitamin A.

Food sources include: Carrots, sweet potatoes, pumpkin, and other yellow or orange fruits and vegetables. Dark green leafy vegetables also contain significant amounts.
Absorption note: Provitamin A from plants is less bioavailable than preformed vitamin A from animal sources. Pairing carotenoid-rich foods with healthy fats can enhance absorption.

Vitamin C (Ascorbic Acid)

This water-soluble antioxidant is widely available in plant foods and is sensitive to heat.

Food sources include: Citrus fruits, bell peppers, strawberries, kiwi, broccoli, and leafy greens.

Vitamin E (Tocopherols and Tocotrienols)

Vitamin E is a fat-soluble antioxidant produced by plants.

Food sources include: Plant-based oils, seeds, nuts, and leafy greens.

Vitamin K

Plants synthesize vitamin K1 (phylloquinone), essential for blood clotting and bone health.

Food sources include: Green leafy vegetables such as kale, spinach, broccoli, and Brussels sprouts, as well as some vegetable oils.
Important note: Vitamin K2 is mainly from animal products or fermented foods like natto. Absorption is improved when consumed with fat.

B-Complex Vitamins

Most B-complex vitamins are abundant in plants and function as cofactors in metabolism.

B1 (Thiamine): Found in whole grains, nuts, seeds, and legumes.
B2 (Riboflavin): Rich sources include almonds, mushrooms, and leafy greens.
B3 (Niacin): Found in brown rice, nuts, seeds, and legumes.
B5 (Pantothenic Acid): Available in mushrooms, avocados, and broccoli.
B6 (Pyridoxine): Sourced from chickpeas, bananas, and dark leafy greens.
B7 (Biotin): Found in sweet potatoes, nuts, and avocado.
B9 (Folate): Abundant in dark leafy greens, beans, and oranges.

Vitamins Requiring Special Attention in Plant-Based Diets

While a plant-based diet is nutrient-dense, two vitamins require careful planning or supplementation.

Vitamin B12 (Cobalamin)

Vitamin B12 is crucial for nerve function and blood formation. It is not reliably found in natural plant foods, as it is produced by bacteria.

Solution: Vegans must regularly consume vitamin B12 through fortified foods or take a supplement.

Vitamin D

Most people obtain vitamin D through sun exposure, and animal products are a primary dietary source. While some mushrooms contain vitamin D2 after UV exposure and vegan D3 supplements exist, dietary plant sources are limited.

Solution: Reliance on fortified plant milks and cereals, sun exposure, and/or supplementation is often necessary.

Comparison of Plant-Sourced vs. Synthetic Vitamins

Here is a comparison of different vitamin sources based on key factors.


Feature	Plant-Based Vitamins (from whole foods)	Synthetic Vitamins	Fortified Foods (Plant-Based)
Source	Fruits, vegetables, nuts, seeds, legumes	Lab-produced chemicals	Plant milks, cereals, and other products with added nutrients
Bioavailability	Variable, can be enhanced by natural co-factors.	Depends on the specific chemical form and dosage; lacks natural co-factors.	High for specifically added nutrients (like B12); depends on the food.
Co-nutrients	Rich in synergistic phytonutrients, fiber, and other compounds.	None. Isolated nutrients only.	Varies depending on the base product.
Dietary Suitability	Excellent for vegetarian, vegan, and flexitarian diets	Can be suitable for all diets	Essential for specific nutrients like B12 on a vegan diet.

Tips for Maximizing Vitamin Intake from Plants

Eat the Rainbow: Consume a wide variety of colorful fruits and vegetables for diverse nutrients.
Combine with Healthy Fats: Pair fat-soluble vitamin sources (A, E, K) with healthy fats to increase absorption.
Choose Whole Grains: Opt for whole grains for a wider spectrum of B vitamins, fiber, and minerals.
Strategize with Fortified Foods: Include fortified nutritional yeast, cereals, or plant milks for B12.
Store and Cook Smart: Preserve heat-sensitive nutrients like vitamin C by consuming some foods raw and using steaming or microwaving.
Diversify Your Legumes: Incorporate various beans, lentils, and pulses for a range of B vitamins, iron, and protein.

Conclusion

A diet based on a wide array of plant foods provides the vast majority of essential vitamins. Through a diverse intake of fruits, vegetables, legumes, whole grains, nuts, and seeds, you can easily meet your needs for vitamins A, C, E, K, and most B vitamins. For specific nutrients like B12, which are not reliably present in plants, relying on fortified foods and supplements is necessary for nutritional completeness. By understanding which vitamins come from plant sources and planning accordingly, a plant-based diet can be both healthy and sustainable. For further reading on the function of plant vitamins, see this Frontiers in Plant Science Review.

Frequently Asked Questions

Vitamin B12 is not naturally found in plants. Vitamin D is also not reliably available from plant-based foods, aside from some UV-exposed mushrooms and fortified products.

Vegans can get enough vitamin B12 by consistently consuming fortified foods, such as nutritional yeast, plant-based milks, and breakfast cereals. Regular supplementation is often recommended.

Yes, some plant-sourced vitamins have different bioavailability. For example, provitamin A from plants is less efficiently converted compared to preformed vitamin A from animal sources. However, bioavailability of fat-soluble vitamins like K increases with fat consumption.

The best plant sources of vitamin C include citrus fruits, bell peppers, strawberries, kiwi, and broccoli. To maximize intake, consume these foods raw, as heat can destroy the vitamin.

Maximize absorption by eating a wide variety of colorful plants. Pair fat-soluble vitamins (A, E, K) with healthy fat. Minimize heat exposure for heat-sensitive vitamins like C.

Yes, most B-complex vitamins are widely available in plants. Good sources include whole grains, legumes, nuts, seeds, and leafy green vegetables.

Yes, you can easily get vitamin K1 from a plant-based diet. Excellent sources include kale, spinach, broccoli, and collard greens. Small amounts of vitamin K2 are in fermented soy products like natto.