From the Guidelines
The daily recommended intake levels of Vitamin C (Ascorbic Acid) are 90 mg/d for men and 75 mg/d for women, as recommended by the USA and Canada, while the recommended intake of Zinc is not specified in the provided evidence.
Vitamin C Intake
- The recommended dietary allowance (RDA) for vitamin C varies globally, ranging from 40 mg/d in the UK and India to 110 mg/d in some European countries 1.
- The RDA is defined as the average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97-98%) healthy individuals in a particular life stage and gender group 2.
- The USA and Canada's RDA of 90 mg/d for men and 75 mg/d for women is based on the potential health effects of vitamin C, including antioxidant protection and maintenance of near-maximal neutrophil concentrations with minimal urinary excretion of ascorbate 1.
Zinc Intake
- Unfortunately, the provided evidence does not specify the recommended daily intake levels of Zinc.
- However, it is essential to note that Zinc is an essential nutrient, and its recommended intake may vary depending on factors such as age, sex, and life stage.
- Further research is needed to determine the recommended daily intake levels of Zinc.
From the Research
Vitamin C (Ascorbic Acid) Intake
- The recommended dietary allowance (RDA) of vitamin C has been a topic of discussion, with some studies suggesting an increase from the traditional 60 mg/day to 90-100 mg/day for optimum reduction of chronic disease risk in nonsmoking men and women 3.
- Other studies propose an RDA of 120 mg/day based on an estimated average requirement (EAR) of 100 mg/day 4, 5.
- The adequate intake (AI) amount is estimated to be either 200 mg/day from 5 servings of fruits and vegetables or 100 mg/day of vitamin C to prevent deficiency with a margin of safety 4.
- The tolerable upper intake level is proposed to be less than 1 g of vitamin C daily 4, 5.
- Some studies suggest that individuals with chronic diseases, such as cancer or diabetes, or those who smoke may require higher doses of vitamin C in their diet 6.
Zinc Intake
- There is no information available in the provided studies regarding the daily recommended intake levels of Zinc.
Comparison of Recommendations
- The recommended daily intake of vitamin C varies across studies, with proposed RDAs ranging from 90 mg/day to 120 mg/day 3, 4.
- The AI amount is estimated to be 200 mg/day from 5 servings of fruits and vegetables or 100 mg/day of vitamin C to prevent deficiency with a margin of safety 4.
- It is essential to note that the current recommendation of daily intake of vitamin C is 90 mg/d for men and 75 mg/d for women, as stated in one of the studies 6.