Citrus is best known for vitamin C, but that’s only part of what an orange or a lemon brings to a meal. The form matters, too: peeling a piece of fruit for a snack isn’t quite the same as pouring a glass of juice.

Some citrus fruits are best eaten by the segment, while others are more useful for seasoning. Knowing what each part of the fruit offers makes it easier to decide what to eat, what to squeeze, and what to grate.

Vitamin C and Iron

A medium orange delivers roughly 70 milligrams of vitamin C, which covers most of what a person typically needs in a day. Vitamin C helps the immune system work normally. It also has a role at mealtimes that’s easy to overlook.

According to Tori Erickson, a dietitian at Mayo Clinic Health System, the vitamin C in citrus helps the body absorb more iron from plant foods eaten at the same meal. Try orange segments in a spinach salad, or serve an orange alongside a meal that includes beans or lentils.

Fiber in the Pith

The pith, the white, spongy layer under the peel, contains fiber. The flesh contributes fiber too, so leaving a little pith attached doesn’t mean eating the outer peel. Once you’ve peeled an orange, there’s no need to scrape the white threads off every segment.

A whole navel orange provides about 3 grams of fiber, while a cup of freshly squeezed orange juice contains 0.5 grams. Squeezing leaves much of the fiber behind with the pulp and membranes. That doesn’t mean the juice is nutritionally empty: it still provides vitamin C and potassium.

Potassium in Citrus

Bananas tend to get the attention, but a navel orange contains 232 milligrams of potassium. Potassium helps regulate blood pressure. Citrus can contribute to overall intake alongside foods such as beans and leafy greens, but adding an orange to a meal doesn’t reduce the sodium already in it.

Choosing Citrus

Oranges and mandarins are sweet enough to eat whole, while the tart juice of lemons and limes works well in dressings or on fish. If you’re buying oranges for snacking, navels are usually seedless. Valencia oranges can have a few seeds, so check the segments before tossing them into a salad.

Choose oranges that feel heavy for their size and have no soft spots. A surface scar needn’t rule out an otherwise firm orange: it can come from the fruit rubbing against a branch as it grows, without affecting the flesh inside.

Grapefruit and Medicines

Grapefruit and its juice can affect how certain medicines work, including some statins. Grapefruit can slow the breakdown of some medicines, so more of the drug reaches the bloodstream. With some other medicines, it can have the opposite effect and reduce the amount the body absorbs.

The interaction depends on the specific medicine. If you take medication, check the patient leaflet or ask a pharmacist whether grapefruit is safe with it. If you’ve been told to avoid grapefruit, ask about pomelos and tangelos too, since they can cause similar interactions.

Using Citrus in Meals

Keep a bowl of mandarins or clementines where you’ll see them. They’re easy to peel by hand and pack for a snack. At lunch, toss orange segments into a salad with olive oil and a pinch of salt, or use lemon juice in the dressing.

Add lemon zest to rice or roasted vegetables. Zest is the colored outer layer of the peel, where the fragrant oils are. Grate just that layer and stop when the white pith shows. Zest gives a dish the scent of lemon without adding the tartness of a squeeze of juice.

If you’re packing orange segments for later, rinse and rub the fruit under running water before peeling it. Keep the peeled segments covered in the refrigerator until you’re ready to pack them.