Vitamin C

Vitamin C is a powerful internal antioxidant that supports lymphocyte and natural killer cell activity, as well as white blood cell production (associated with a strong immune system).

Your body cannot make vitamin C on its own, so you have to get it from food and/or supplements. It's essential for numerous bodily processes, including bond and connective tissue health.  Vitamin C also increases the body's absorption of iron and regenerates vitamin E.

You can reduce the frequency and duration of colds and the flue, particularly in extreme athletes and those living in cold climates; boost energy; alleviate allergies; strengthen bones; enhance collagen production; and reduce your cancer risk.

Daily dosage vary widely for every person. In general, at least 1,000 mg of vitamin C and up to 15,000 mg daily can be used.  Abdominal bloating, gas, and loose stools are signs that you've taken more than your body can absorb.

Ester-C is a proprietary form of vitamin C that is non-acidic and highly absorbable. It is available in capsules and powders.

Signs that you need more vitamin C:

• Low energy/fatigue
• Poor/slow wound healing
• Frequent colds and/or infections
• Lung problems

There are also a lot of great ways to get more vitamin C in your diet just from the foods you eat. 

• Papaya
• Bell Peppers
• Strawberries
• Broccoli
• Cauliflower
• Lemon Juice
• Pineapple
• Brussels Sprouts
• Kiwi
• Kale

Source: betternutrition