- You can take vitamin C at any time of day, but taking it after meals may help reduce stomach irritation.
- For better absorption, dietitians recommend liposomal and whole-food formulations.
- A food-first approach is best with vitamin C—focus on foods like red peppers, mango, papaya, oranges and Brussels sprouts.
Vitamin C is one of the most well-known vitamins, celebrated for supporting the immune system and promoting healthy skin. While citrus fruits are often the go-to source, some people turn to supplements to meet their daily needs. If you’re planning your supplement routine, you may wonder if there’s a best time to take vitamin C to maximize its benefits and minimize side effects. To help, we spoke with registered dietitians to share expert advice on optimal timing for taking vitamin C and how to get the most out of your supplement.
What Is Vitamin C?
Vitamin C is a water-soluble vitamin that is essential for several key processes in the human body. “It protects DNA from oxidative damage, contributes to collagen production and plays an important role in maintaining a healthy immune system. Vitamin C also enhances the absorption of certain minerals, particularly iron, making it critical for overall nutrient balance,” says Katie Calderone, RDN, CPT, a registered dietitian.
Because the body cannot produce vitamin C or store it in large amounts, it must be consumed on a regular basis. The recommended daily intake is 90 milligrams for men and 75 mg for women, with higher needs during pregnancy, lactation or periods of illness. “While most people can meet their needs through diet, some groups are at higher risk of deficiency and may benefit from supplementation,” Calderone explains.
She highlights that people who smoke and those exposed to secondhand smoke experience increased oxidative stress, which raises their vitamin C needs by an additional 35 mg over the recommended amount. Similarly, “chronic stress increases the body’s demand for vitamin C, as this nutrient is rapidly used during the stress response,” she adds. In rare cases, people who consume very few fruits and vegetables may need to supplement to reach adequate levels.
Morning vs. Evening
Here’s the good news: there isn’t a single “best” time to take vitamin C. “Vitamin C can generally be taken at any time of day,” says Holli Ryan, RD, LDN, a registered dietitian. There’s no strong evidence that taking vitamin C supplements in the morning versus the evening affects how well the body absorbs or uses it. Since vitamin C is water-soluble, it’s absorbed relatively quickly, and any excess comes out through urine.
“Where timing does make a difference is in relation to meals, since vitamin C enhances the absorption of minerals, particularly non-heme iron from plant foods,” says Calderone. Non-heme iron, found in plants, isn’t absorbed as efficiently as the iron in animal products. To increase absorption, pair plant-based iron with vitamin C-rich foods. Calderone notes that this can help reduce the risk of iron-deficiency anemia, which is especially important for vegetarians, vegans and menstruating women.
Ryan adds that it’s best to take your vitamin C supplement after a meal to help prevent stomach irritation, which can occur if it’s taken on an empty stomach. “If you have a sensitive stomach, consider buffered vitamin C, which is vitamin C with minerals that can help neutralize acid and avoid irritation to the stomach lining,” she explains.
Factors to Consider When Deciding to Supplement
Type of Vitamin C
Vitamin C supplements are sold in various forms, with ascorbic acid being the most common. Synthetic ascorbic acid supplements are affordable and widely available, making them a practical option for most people. However, Calderone recommends choosing vitamin C supplements made from whole-food sources like acerola cherry, camu camu, amla, rosehip, citrus bioflavonoid blends or freeze-dried fruit powders. “In nature, vitamin C comes packaged with bioflavonoids and phytonutrients that enhance its activity and retention in the body,” she explains.
To further support absorption, Ryan suggests looking for liposomal formulas or formulas with quercetin. Liposomal formulas use tiny fat-like carriers called liposomes, which help protect vitamin C from degradation during digestion and improve absorption. Research shows that liposomal vitamin C can lead to higher levels in both blood plasma and leukocytes (immune cells) compared to standard vitamin C supplements.
Risks and Precautions
Although vitamin C supplementation is generally safe, taking high doses above 2,000 mg per day can pose some risks. These include digestive issues such as abdominal cramps, diarrhea, nausea and gut disturbances. Both dietitians also note that high doses may increase oxalate and uric acid excretion, which can contribute to kidney stone formation in individuals with kidney disorders. “Vitamin C also enhances the absorption of plant-based iron, which can be beneficial for individuals with anemia but may be harmful in conditions such as hemochromatosis, where iron overload is already a concern,” says Calderone.
Individuals taking certain medications should also exercise caution with vitamin C supplementation. Vitamin C supplements can negatively interact with radiation therapy, chemotherapeutic medications and statins. To make sure it’s right for you, always consult your health care provider before adding the supplement to your daily regimen.
Food Sources of Vitamin C
While supplements offer convenience, a food-first approach is generally best for meeting your vitamin C needs. This essential nutrient is abundant in many fruits and vegetables, making it easy to get through a balanced diet. Some excellent sources of vitamin C include:,
- Bell peppers
- Guava
- Mango
- Papaya
- Oranges
- Kiwis
- Strawberries
- Pineapple
- Grapefruit
- Cantaloupe
- Broccoli
- Brussels sprouts
- Kale
- Cabbage
- Cauliflower
Calderone warns that food preparation and cooking can reduce the vitamin C content of foods: “Because vitamin C is water-soluble and heat-sensitive, cooking fruits and vegetables can reduce their content by about 15% to 55%. Boiling causes the greatest loss, while steaming and microwaving help preserve more.”
Our Expert Take
The verdict is in: vitamin C can be taken at the time of day that works best for you. To maximize its benefits and prevent digestive discomfort, it’s best to take it after a meal. For enhanced absorption and effectiveness, opt for liposomal formulations and whole-food supplements. However, you should always speak to your health care provider to ensure supplementation is safe for you. Most importantly, prioritizing fruits and vegetables first can help you naturally meet your vitamin C needs while also providing a range of other beneficial nutrients.
