WHEN IS THE BEST TIME TO TAKE VITAMIN C?

Vitamin C is a health superstar. It’s essential for healthy skin, bones, teeth and gums. It supports the immune system, and helps the body absorb iron and heal wounds. It’s a strong antioxidant that protects cells from damage.

The human body can’t make vitamin C, so we have to get it through diet or supplements.

Registered dietitian Carol Johnston, Ph.D., who is an expert on vitamin C metabolism, always recommends getting the nutrient from fresh fruits and vegetables. But “fresh” is key because vitamin C is destroyed when food is processed or exposed to heat, light or oxygen, she notes.

“I say, just go ahead and supplement even if you think you might be OK because you eat lots of fruits and vegetables,” Johnston, a professor of nutrition at Arizona State University, tells TODAY.com.

“You have to eat specific fruits and vegetables — it’s not just apples and bananas and lettuce. You have to eat broccoli and bell peppers.”

When taking vitamin C supplements, what is the best time to do so? Here’s what the experts say:

How much vitamin C per day do you need?

The recommended daily intake of vitamin C is 90 milligrams for men and 75 milligrams for women, according to the National Institutes of Health. Children need less.

Pregnant women should get 85 milligrams a day; and the amount rises to 120 milligrams for those who are lactating.

To put that in context, one whole grapefruit has 90 milligrams of vitamin C. One yellow bell pepper has 342 milligrams of vitamin C.

The safe upper limit of vitamin C intake is 2,000 milligrams a day, though the nutrient has “low toxicity” and doesn’t cause serious problems even at high doses, the NIH notes. The most common side effects are diarrhea, nausea, abdominal cramps and other gastrointestinal issues.

Vitamin C is water-soluble, which means it can dissolve in water and is not stored by the body — the excess is flushed out in urine.

What is the best time to take vitamin C?

When it comes to the time of day, there’s no best time — any time is fine to take vitamin C supplements, Johnston says.

But there are two things to keep in mind:

Stomach discomfort

If you find the vitamin C supplement irritates your stomach, take it with a meal.

About 10% of participants in Johnston’s studies complain about discomfort in their gastrointestinal tract or diarrhea, but the problems go away when they take the supplement with food, she notes.

Absorption

The body has a system to absorb vitamin C in the gut, but there’s a limit to that absorption capacity, Johnston says. If you take too much of the nutrient at once, you overload the system, and the excess is excreted in the urine.

So it may be helpful to divide your total dose — take half in the morning and half in the evening — to maximize the amount that gets into the bloodstream, Johnston says.

A total daily vitamin C dose of 200 milligrams taken in divided doses has nearly complete absorption, studies have found.

What is the best time of the year to take vitamin C?

The cold and flu season is a particularly good time.

Vitamin C is a powerful antioxidant that can boost the immune system, says Elisabetta Politi, a registered dietitian at the Duke Lifestyle and Weight Management Center in Durham, North Carolina.

It reduces the severity of common colds, and taking 200 milligrams or more of vitamin C a day shortens their duration by about 10%, studies have found.

Regular vitamin C supplementation had a “modest but consistent effect” in helping cold symptoms go away quicker, researchers note.

When it comes to preventing a cold, supplementing has the biggest effect on people who already have a vitamin C deficiency, or are under stress like marathon runners or soldiers in boot camp. Vitamin C halves their common cold risk, Johnston says.

Vitamin C is also an antihistamine, so it can alleviate congestion, eye itching, runny nose and other cold and flu symptoms, she adds.

For that reason, allergy season is another good time of year to take vitamin C supplements.

“When I have my seasonal allergies, I do consume extra vitamin C. I’m not going to take an antihistamine because it will make me drowsy, and vitamin C doesn’t make you drowsy,” Johnston says.

“Vitamin C doesn’t really have any side effects. … I swear by it.”

Vitamin C dosage per day

Consider taking 200-500 milligrams of vitamin C per day in supplement form during cold and flu season, in addition to eating lots of vitamin C-rich foods, registered dietitian and TODAY nutrition expert Joy Bauer advises.

Johnston had the same advice. 

Food sources of vitamin C

Foods high in vitamin C include:

• Citrus fruits
• Kiwi
• Red and yellow bell peppers
• Tomatoes
• Broccoli
• Cabbage
• Cauliflower

Eating five servings a day of a variety of fruits and vegetables provides "ample amounts" of vitamin C — about 200 milligrams or more, studies have found.

Diets with that amount of vitamin C from fruits and vegetables are associated with lower cancer risk, researchers note. Taking vitamin C supplements doesn’t seem to have the same protective effect, according to the NIH.

This article was originally published on TODAY.com

2025-01-24T16:45:07Z