Boost Immunity with Vitamin C

We are officially in cold and flu season. It’s not something to celebrate, but it is a great time to talk about a vitamin that is particularly helpful this time of the year.

Vitamin C (fancy name=ascorbic acid) is a water-soluble vitamin that supports normal growth and development. Vitamin C is not only associated with preventing illness and boosting immunity, but it plays other important roles within the body: helping with the absorption of iron from foods, acting as a protector of cells, protecting the body from bruising, encouraging wound healing, keeping your gums healthy, and producing collagen. But because your body doesn’t produce or store vitamin C (it is eliminated from the body when it’s not needed), it’s critical that you get it from foods in your daily diet.

In my house, we’ve already suffered from a few colds and viruses this year so I know we need to bump up our vitamin C intake—citrus, here we come!

How much?

Individuals vary greatly in their requirement for vitamin C. A person's age and health status can dramatically change his or her need for vitamin C. For example, one person might need 10 times as much vitamin C as another person. But in general, The Dietary Reference Intakes (DRIs) provide the following guidelines regarding the amount of vitamin C you should get from both the food you eat and the supplements you take:

• 0-6 months: 40 mg/day
• 7-12 months: 50 mg/day
• 1-3 years: 13 mg/day
• 4-8 years: 22 mg/day
• 9-13 years: 39 mg/day
• 14-18 year males: 63 mg/day
• 14-18 year females: 56 mg/day
• Adult males: 75 mg/day
• Adult females: 60 mg/day
• Pregnant: 70 mg/day

What foods?

The amount of vitamin C found in foods varies as dramatically as our human requirement. In general, an unripe food is much lower in vitamin C than a ripe one. Vitamin C is very sensitive to temperature, air, and water. About ¼ of the vitamin C in fruits and vegetables can be lost simply by boiling and steaming for a few minutes, and by freezing and thawing. Cooking vegetables and fruits for longer periods of time (10-20 minutes) can result in a loss of over ½ the total vitamin C content.

Excellent dietary sources of vitamin C include: parsley, broccoli, bell pepper, strawberries, oranges, lemon juice, papaya, cauliflower, kale, mustard greens, potato, cabbage, carrots, avocado, asparagus, beets and Brussels sprouts (my personal favorite veggie!). The best way to ensure adequate vitamin C intake is to eat at least 5 a day of fruits and vegetables—the more the better!

Not enough?

Vitamin C deficiency results in a disease called scurvy, which is rare in the U.S. Symptoms include bleeding gums and skin discoloration. A more common symptom of a vitamin C deficiency is poor wound healing (but this might also be associated with other factors). Weak immune function, including susceptibility to colds and other infections, can also be associated with vitamin C deficiency.

How much is too much?

Vitamin and mineral supplements should always be used with caution, particularly with children. Large doses of vitamin C (although not usually toxic due to the fact that it is a water soluble vitamin and leaves your body in urine) can cause some unpleasant side effects such as stomach upset, diarrhea, and kidney stones. Take caution when supplementing vitamin C in children and avoid exceeding these limits:

• 1-3 years: 400 mg/day
• 4-8 years: 650 mg/day
• 9-13 years: 1200 mg/day
• 14-18 years: 1800 mg/day

The upper limit of vitamin C in infants less than one year is undetermined.

As always, offer your children (and yourself) a healthful diet that follows the principles of balance, variety, and moderation. Remember that it’s your job as the parent to offer the foods, and your children’s jobs to determine if and how much they will eat. Chances are, if they are growing and developing and you are being a good food role model, they will get all of the nutrients that they need!

Be well, be NutritionWise!

~ Nicole Meadow, MPN, RD of NutritionWise

This post is solely for informational purposes. It is not intended nor implied to be a substitute for medical advice. Before undertaking any course of treatment or dietary changes, you should seek the advice of your physician or other health care provider.