Vegan diets usually include some excellent sources of vitamin A–but it many take a little bit of planning to make sure you get enough on a regular basis.

While vegans don’t have any preformed vitamin A in their diet (it’s only in animal foods), it can be synthesized from compounds called carotenoids found in plant foods. The best known and most biologically active carotenoid is beta-carotene.

As recently as ten years ago, nutrition researchers believed than 6 micrograms of beta-carotene produced one microgram of active vitamin A. But newer research on absorption of carotenoids shows that it actually takes twice that much—12 micrograms of beta-carotene—to produce a microgram of vitamin A. That means that vegan intake of carotenoids is actually only about half the amount reported in earlier studies.

Vitamin A content of foods is measured as retinol activity equivalents (RAE) which is the amount of potential vitamin A activity in a food. Recommended intakes for vitamin A are 700 RAE for women and 900 RAE for men.

Meeting vitamin A requirements may actually be a little bit of a challenge unless you consume at least one very good source of this vitamin every day. The best foods for vitamin A are leafy green veggies, sweet potatoes and, of course, carrots.

In addition to making sure you’re getting enough of these vitamin A-rich foods in your diet, it’s also important to include small amounts of fat with meals and to cook some of your vegetables to enhance absorption of carotenoids. This is one more reason why raw foods diets and low fat diets are not the best choices for vegans.

Here are the best sources of vitamin A with the RAEs shown for each.

Apricots, 3 raw (102)

Hubbard squash, ½ cup mashed (236)

Cantaloupe, 1 cup chunks (270)

Collards, ½ cup cooked (386)

Kale, ½ cup cooked (442)

Spinach, ½ cup cooked (472)

Butternut squash, ½ cup cooked (572)

Carrots, ½ cup cooked (665)

Sweet potatoes, ½ cup cooked mashed (1291)