How Much Vitamin C You Need Every Day—and the Best Ways to Eat It, According to Nutrition and Immunity Experts

Here's every important fact to know about vitamin C, including the best food sources of vitamin C, how much is too much, and the effectiveness of that daily Emergen-C habit.

Assorted citrus fruits stack still life.
Photo: Lee Pei Ling/Getty Images

Immunity is top of mind for many of us, as it certainly should be. In addition to proper hand-washing, getting enough sleep, and exercising regularly, one of the best ways to keep your immune system in fighting shape is to nosh on a balanced array of whole, nutrient-dense foods that offer immunity-boosting minerals (like iron, zinc, and iodine) and vitamins, including (but not limited to!) vitamin C. But before you start topping your pancakes with trendy elderberry syrup and chugging Emergen-C, it's important to understand the most important vitamin C facts so your eating-for-immunity habits can be as healthy and effective as possible.

We asked nutrition and immunity experts from the International Food Information Council our top, burning questions about vitamin C, one of the most well-known immunity-boosting nutrients. Here's everything you should know about this important vitamin, including how it benefits your immune system, how much you need everyday, how much is too much, and the healthiest, high-vitamin C foods to eat.

What is Vitamin C, and what are its health benefits?

"Vitamin C is a water-soluble vitamin that acts as a potent antioxidant," says Megan Meyer, PhD, microbiologist and nutritional immunologist, science communications consultant, and former director of science communication at the International Food Information Council. "It plays an important role in the nervous system, metabolism, and immunity." Additionally, vitamin C helps with micronutrient absorption, especially iron. Since your body doesn't produce its own vitamin C, you have to get it from food sources (or supplements).

How much vitamin C do you need each day?

According to Meyer, the recommended dietary allowances (RDAs)—the daily amount of a nutrient that meets the needs of most people—for vitamin C range from 15 milligrams to 120 milligrams per day, depending on factors like age and sex. The RDA for vitamin C is set at around 90 milligrams per day for men and 75 milligrams per day for women, although the RDA is higher if you're pregnant and/or breastfeeding. (To see specific RDAs, check out Meyer's article here.)

"Also of note: Vitamin C used to be listed on the nutrition facts label, but is no longer required since, on average, most Americans consume enough vitamin C each day," Meyer says.

RELATED: 5 Healthy Foods That Are High in Vitamin D (and Why It's So Important to Eat Them)

What are the best food sources of vitamin C?

According to Meyer, high amounts of vitamin C can be found in a variety of easy-to-find vegetables and fruits, including:

Here are more delicious ways to eat lots of vitamin C.

Should you double up on vitamin C to boost immunity?

"Vitamin C is an important nutrient for optimal immune function. However, studies have shown that taking megadoses of [vitamin C] in supplement form doesn't actually do any good when it comes to fighting off illnesses, like the common cold," explains Ali Webster, PhD, R.D., senior director of research and nutrition communications for the International Food Information Council.

Webster explains that more vitamin C isn't necessarily better because the body can absorb only a few hundred milligrams of it at a time. Again, the RDA for vitamin C is 75 milligrams for women and 90 milligrams for men, and "any amount above this is excreted in the urine," she says.

Can you take too much vitamin C?

A vitamin C overdose is unlikely, but that doesn't mean chugging Emergen-C five times a day is worth it. "Since vitamin C is water-soluble, it has low toxicity and is not linked to adverse effects at high doses," Meyer says. "However, the Food and Nutrition Board at the Institute of Medicine of the National Academies has established a Tolerable Upper Intake Level (aka UL) for vitamin C, stating that long-term intake of vitamin C above this amount may increase the risk of adverse health effects." Similar to the RDAs shared above, your body's UL depends on your age and sex. To find the specific vitamin C UL for you, see the National Institutes of Health guidelines here.

However, if you're taking certain medications, you'll need to be extra cautious with vitamin C supplements. "Vitamin C supplements may interact with several types of medications such as statins, chemotherapy, and radiation," Meyer says. "Regardless of your medical history and dosages, everyone should be sure to consult with their healthcare provider before taking vitamin C supplements."

Was this page helpful?
Real Simple is committed to using high-quality, reputable sources, including peer-reviewed studies, to support the facts in our articles. Read our editorial guidelines to learn more about how we fact check our content for accuracy.
  1. NIH-Office of Dietary Supplements, Vitamin C Factsheet for Health Professionals. Accessed July 26, 2022.

  2. Gómez E, Quidel S, Bravo-Soto G, et al. Does vitamin C prevent the common cold?. Medwave. 2018;18(4):e7235. doi:10.5867/medwave.2018.04.7236

Related Articles