Beans are one of the richest plant sources of B vitamins, particularly folate (vitamin B9). A half cup of cooked pinto beans delivers 147 micrograms of folate, roughly 37% of the daily recommended intake for adults. Beyond folate, beans supply smaller but meaningful amounts of vitamin K, and when sprouted, they can produce significant vitamin C.
Folate: The Standout Vitamin in Beans
Folate is the vitamin beans are best known for. Your body uses it to make DNA, produce red blood cells, and support cell division. It’s especially important during pregnancy, when inadequate folate increases the risk of neural tube defects. The daily value for adults is 400 micrograms.
Here’s how common varieties stack up per half cup of cooked beans:
- Pinto beans: 147 mcg (37% DV)
- Black beans: 128 mcg (32% DV)
- Navy beans: 127 mcg (32% DV)
- Red kidney beans: 115 mcg (29% DV)
- Black-eyed peas: 105 mcg (26% DV)
One thing to note: canned beans tend to have lower folate levels than beans you cook from dried. Canned kidney beans, for example, contain about 46 mcg per half cup, roughly a third of what you’d get from cooking dried kidney beans yourself. The canning process, which involves high heat and extended time in liquid, leaches water-soluble vitamins like folate. If maximizing your vitamin intake matters to you, cooking from dried beans is the better option.
Other B Vitamins in Beans
Folate gets the headlines, but beans also contain thiamine (B1), which helps convert food into energy, and vitamin B6, which plays a role in immune function and brain development. The amounts vary by variety, but most cooked beans provide a modest contribution toward your daily needs for these vitamins. They won’t single-handedly cover your B vitamin requirements, but as part of a varied diet, they add up meaningfully, especially if you eat beans regularly.
Vitamin K in Beans
Vitamin K, which your body needs for blood clotting and bone health, shows up in beans in varying amounts. It’s a fat-soluble vitamin, so it’s not typically what people associate with legumes, but certain types deliver a respectable dose.
Black-eyed peas lead the pack among common beans, with about 44 to 63 mcg per cup depending on whether they’re fresh or frozen. Green snap beans provide around 51 mcg per cup. Most mature dried beans like black beans and lima beans fall in the 6 to 12 mcg range per cup, which is a smaller contribution. For context, the daily adequate intake for vitamin K is 120 mcg for adult men and 90 mcg for adult women. So black-eyed peas can cover a significant portion of your daily needs, while standard dried beans offer a more modest amount.
Vitamin C: Only When Sprouted
Dried or cooked beans contain essentially no vitamin C. But something interesting happens when you sprout them. During germination, beans begin producing ascorbic acid (vitamin C) rapidly. After about four days of sprouting, mung beans, green lentils, and black-eyed beans can reach 140 to 200 milligrams of vitamin C per gram of fresh sprout weight. That’s a dramatic shift from zero.
Research published in the European Journal of Clinical Nutrition found that sprouting roughly half the beans in a basic food ration for three to five days could generate enough vitamin C to prevent scurvy. There’s a catch, though: cooking destroys much of the vitamin C that sprouting creates. If you’re eating sprouts for their vitamin C content, consuming them raw or very lightly cooked preserves the most.
What Beans Don’t Provide
Beans are not a meaningful source of several vitamins people commonly look for. They contain virtually no vitamin A, vitamin D, vitamin E, or vitamin B12. Vitamin B12 is only found naturally in animal products and certain fortified foods, so this gap matters most for people eating a fully plant-based diet. Vitamin D comes primarily from sunlight exposure, fatty fish, and fortified foods. If beans are a staple in your diet, these are the vitamins you’ll need to get elsewhere.
How Preparation Affects Vitamin Absorption
Beans contain phytic acid, a compound that binds to minerals like iron, zinc, and calcium in your gut, reducing how much your body absorbs. Phytic acid doesn’t directly block vitamin absorption, but since beans are often valued for their mineral content alongside their vitamins, it’s worth understanding how to minimize its effects.
Soaking beans overnight before cooking breaks down a significant portion of phytic acid. Sprouting does even more, as germination activates enzymes that dismantle phytates naturally. Fermentation and pickling also reduce phytic acid levels. Even simple cooking helps. These preparation steps don’t just improve mineral absorption. Soaking and cooking also make the beans more digestible overall, which can help your body access the B vitamins and other nutrients more efficiently.
The practical takeaway: if you’re relying on beans as a nutritional cornerstone, cooking them from dried (after an overnight soak) gives you the best combination of high folate content and improved nutrient availability. Canned beans are convenient and still nutritious, but you’re trading some vitamin content for that convenience.