Vitamin C is a water soluble vitamin and it has many roles in the body - it acts as an antioxidant, it helps to make nerve chemicals called neurotransmitters, and it helps to maintain cartilage health.
Adequate blood levels of Vitamin C is 49-58 micromoles/Litre, blood levels less than 28 micromoles/Litre is considered to be a Vitamin C inadequacy, levels less than 11 micromoles/Litre is considered a deficiency.
Inadequate levels of vitamins C decrease immune system strength
Low Vitamin C levels in the body lead to an overall decrease in immune system strength and also produces a reduced desire to engage in physical activity. A new study published in November 2014 suggests that Vitamin C supplementation may improve both physical activity and immune system strength.
The study was undertaken with 28 healthy non-smoking adult men aged 18 to 35, who had pre study Vitamin C levels of below 45 micromoles/Litre. The subjects received either 1000mg of Vitamin C or a placebo daily over an 8 week period. Every week the subjects completed a survey to assess Upper Respiratory symptoms and a questionnaire to assess leisure time exercise.
The researchers noted that by week 8 physical activity scores rose for the Vitamin C group compared to the placebo group (60.2% and 20.5% respectively) and 37.4% fewer subjects reported colds compared to the placebo group. Furthermore the duration of a cold was 59.6% shorter in the Vitamin C group.
How Vitamin C reduces the duration of colds remains unknown but researches think it may be down to the improved action of the immune system's natural killer cell activities and lymphocytes. The results of the study suggests that there are "..measurable health advantages associated with Vitamin C supplementation in men with adequate to low Vitamin C blood levels" and "..a simple dietary strategy to promote physical activity and physical health merits further research and the consideration of health practitioners."
Dietary sources of vitamin C include the following:
- Oranges - one medium orange contains 70 milligrams of vitamin C and 62 calories. In liquid form, 3/4 cup of orange juice contains 61 to 93 milligrams of Vitamin C and 79 to 84 calories
- Kiwi - one medium kiwi contains 70 milligrams of the nutrient and 46 calories.
- Red peppers - one half cup of the pepper contains 142 milligrams of vitamin C and 20 calories. If you cook it, half a cup offers 116 milligrams.
- Green peppers - Green peppers offer 60 milligrams of vitamin C per half cup, with only 15 calories. When cooked, the vegetable provides 51 milligrams of vitamin C.
- Grapefruit Juice - one half of a grapefruit has 39 milligrams of vitamin C and 52 calories. Three fourths of a cup of grapefruit juice provides 50 to 70 milligrams of vitamin C and 71 to 86 calories.
- Vegetable Juice - drinking your vegetables provides plenty of nutrients, including a vitamin C kick. If your vegetable juice is tomato-based it will provide a healthy dose of lycopene, which is a disease-fighting phytonutrient. 3/4 cup of juice yields 50 milligrams of vitamin C and just 34 calories,
- Strawberries - strawberries are full of fiber and antioxidants, including vitamin C. A half cup of strawberries contains 49 milligrams of the vitamin and 27 calories.
- Brussels Sprouts - always a healthy pick that should not be confined to the festive period! They are packed with both 48 milligrams of vitamin C, 300 micrograms of vitamin K, and just 28 calories.
- Cantaloupe Melon - one quarter of a medium cantaloupe has 47 milligrams of vitamin C and 51 calories
- Guava - one half cup of the fruit contains 188 milligrams of vitamin C and only 56 calories