Key Takeaways
- Vitamin C may be most beneficial when taken two to three times daily with food.
- No evidence indicates that extra vitamin C helps prevent or cure colds and flu. However, it may help reduce the severity of symptoms.
- Most people don’t need a vitamin C supplement if they eat a balanced diet, but smokers and those who are pregnant or breastfeeding may benefit from a little extra.
The best way to take vitamin C to boost your immune system is with meals multiple times daily. Dividing your daily vitamin C intake into smaller doses throughout the day might lead to better absorption and utilization than taking a large dose once daily.
1. Spread Your Doses Throughout the Day
Vitamin C may be most beneficial when taken two to three times daily with food. While there’s no wrong way to take vitamin C supplements, medical experts typically recommend breaking your daily dosage into several small amounts.
The amount of vitamin C supplementation you need will, in part, determine how often you should take it. Talking to a healthcare provider will help you choose the amount you need and the best dosing schedule for you.
2. Any Time of Day Is Fine–As Long As You’re Consistent
Taking vitamin C supplements at any time of day is fine, as there’s no specific “best time” to do so.
Studies indicate that vitamin C supplementation is beneficial for increasing sleep duration and reducing sleep disturbances, such as movement disorders like restless legs syndrome.
Vitamin C’s benefits for sleep are thought to be due to its antioxidant properties, which help protect cells from damage. It may help with overall nervous system functioning and sleep quality. However, it is unclear whether timing impacts these effects.
3. Take It With Meals If It Upsets Your Stomach
Vitamin C supplements are available in various forms, including chewable, capsule, and liquid forms. Vitamin C (in any form) can be taken with meals or on an empty stomach. There’s no significant evidence indicating that one form is better for nutrient absorption than the other.
However, vitamin C is acidic. If you’re prone to heartburn or have a condition like diverticulitis or gastroesophageal reflux disease (GERD), you may be better off taking vitamin C with food.
If you experience stomach discomfort from taking vitamin C, consider opting for buffered or coated tablets. Buffered vitamins contain minerals, like magnesium, that reduce stomach acid. These may be gentler than unbuffered versions of vitamin C.
4. Take It During Cold and Flu Season
No evidence indicates that extra vitamin C helps prevent or cure colds and flu. However, supplementation of 200 to 1,000 milligrams (mg) daily during cold and flu season may help slightly reduce the time you feel sick when you catch a cold.
The effects are mostly in reducing the time spent with severe symptoms, rather than alleviating mild symptoms. It may also help people who undergo extreme physical activity, are in very cold environments, or don’t get enough vitamin C from food.
How Much Should You Take?
When choosing a vitamin C supplement dosage, several factors should be considered, such as age, medications you take, pregnancy, and underlying conditions you may have.
The following chart indicates guidelines for overall vitamin C intake.
| Age | Dosage |
| Birth through 6 months | 40 mg |
| 6 to 12 months | 50 mg |
| Ages 1-3 | 15 mg |
| Ages 4-8 | 25 mg |
| Ages 9-13 | 45 mg |
| Females ages 14-18 | 65 mg |
| Males ages 14-18 | 75 mg |
| Men over 18 | 90 mg |
| Women over 18 | 75 mg |
| Pregnant people over 18 | 115 mg |
| Lactating people over 18 | 120 mg |
Smoking cigarettes has a depleting effect on vitamin C. No matter what your age, experts recommend increasing your intake by 35 mg if you smoke or are routinely exposed to second-hand smoke.
Your diet will impact the amount of vitamin C you need and when you should take it. You may need less if your diet is rich in this nutrient. If you eat a meal containing vitamin C-rich food, you may wish to skip taking a supplement with that meal.
Who Should Avoid It?
Vitamin C supplementation is safe for most people, but not for everyone. Children should not be given vitamin C unless a healthcare provider, such as a pediatrician, recommends it.
Vitamin C is safe for most people to take during pregnancy or breastfeeding, but the recommended dosage should not be exceeded.
People with certain health conditions should avoid taking vitamin C supplements unless their healthcare provider recommends it. These conditions include:
- Before or after angioplasty surgery (opens blocked blood vessels)
- Corn allergy (since most vitamin C is made from corn, check the label for ingredients before use)
- Diabetes (a condition of high blood sugar)
- Glucose-6-phosphate dehydrogenase (G6PD( deficiency (a metabolic disorder)
- Hemochromatosis (a genetic disorder that increases iron absorption)
- Kidney disease
- Sickle cell disease (an inherited blood disorder)
- Thalassemia (an inherited blood disorder)
Drug and Supplement Interactions
Vitamin C supplements are also contraindicated (not recommended) to take with certain medications. They include:
- Antacids that contain aluminum as an ingredient
- Aspirin
- Barbiturates (class of depressant drugs)
- Birth control pills
- Chemotherapy drugs
- Hormone replacement therapy (HRT)
- Jantoven (warfarin)
- Nonsteroidal anti-inflammatory drugs (NSAIDs), including Advil and Motrin (ibuprofen) and Aleve (naproxen)
- Tylenol (acetaminophen)
If you take any of these medications, discuss with a healthcare provider when, how, and how much vitamin C supplementation is appropriate. Do not stop taking any prescribed medications or change their dosages without consulting a healthcare provider.
A Word From Verywell
Vitamin C requirements can be met through a balanced diet that includes a variety of nutrient-rich foods such as bell peppers, cantaloupe, parsley, kale, kiwis, broccoli, and Brussels sprouts.
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