The Role of Vitamin C, Rich Food Sources and RDAs

Vitamin C (ascorbic acid) is a water-soluble vitamin with a wide range of essential functions in the body:

1. Antioxidant Defense:

● Neutralizes free radicals to protect cells from oxidative stress, reducing the risk of chronic diseases like cardiovascular issues, cancer, and neurodegenerative conditions.

● Regenerates other antioxidants, such as vitamin E, enhancing their effectiveness.

2. Collagen Synthesis:

● Essential for producing collagen, a protein that provides structure to skin, bones, cartilage, tendons, and blood vessels.

● Promotes faster healing of wounds and helps maintain skin elasticity.

3. Immune System Boost:

● Enhances the production and function of white blood cells, particularly lymphocytes and phagocytes, which combat infections.

● Potentially shortens the duration of colds when consumed regularly.

4. Improved Nutrient Absorption:

● Increases the absorption of non-heme iron (from plant sources), reducing the risk of anemia.

5. Prevention of Deficiency:

● Severe vitamin C deficiency can lead to scurvy, a condition characterized by bleeding gums, fatigue, poor wound healing, and joint pain. Left untreated, it can be fatal.

Vitamin C is abundant in many fruits and vegetables, making it easy to meet daily needs through a balanced diet:

1. Fruits:

● Citrus Fruits: Oranges (70 mg per medium fruit), grapefruits, lemons and limes.

● Tropical Fruits: Guava (228 mg per 100 g), kiwifruit (93 mg per 100 g), papaya (90 mg per cup), and pineapple.

● Berries: Strawberries (49 mg per ½ cup), blackcurrants (181 mg per 100 g), and blueberries.

2. Vegetables:

● Peppers: Yellow bell peppers (184 mg per 100 g) and red peppers (95 mg per ½ cup raw).

● Cruciferous Vegetables: Broccoli (81 mg per cup cooked), Brussels sprouts (74 mg per cup), and cauliflower.

● Leafy Greens: Kale (23 mg per cooked cup), spinach, and turnip greens.

3. Other Sources:

● Tomatoes, potatoes, and even herbs like parsley and thyme are moderate sources.

The RDAs for vitamin C are established to maintain optimal health and prevent deficiency:

● Adults:

✓ Men: 90 mg/day

✓ Women: 75 mg/day

● Pregnancy: 85 mg/day

● Lactation: 120 mg/day

● Smokers: Require an additional 35 mg/day due to increased oxidative stress.

Upper Limit: While excess vitamin C is generally excreted in urine, consuming more than 2,000 mg/day can cause side effects like diarrhea, nausea, and stomach cramps.

1. Eat Fresh: Consume raw fruits and vegetables, as cooking can significantly reduce vitamin C content.

2. Variety Matters: Include a mix of citrus fruits, berries, and cruciferous vegetables in daily meals.

3. Creative Recipes:

● Add citrus segments to salads.

● Blend smoothies with kiwifruit and spinach for a nutrient-rich drink.

● Snack on bell pepper slices with hummus.

4. Store Smartly: Avoid prolonged storage of fruits and vegetables, as vitamin C degrades over time.

1. Chronic Disease Prevention:

High intake of vitamin C-rich foods may reduce the risk of heart disease and certain cancers.

2. Skin Health:

Reduces wrinkles and promotes a youthful appearance through collagen support.

3. Eye Health:

Combined with other nutrients, vitamin C slows the progression of age-related macular degeneration (AMD).

● NIH Office of Dietary Supplements.

● Cleveland Clinic.

● MyFoodData Vitamin C Chart.