Zinc is an essential mineral that has functions in a wide range of metabolic processes. You need zinc for the proper metabolism of proteins, carbohydrates and fats. Zinc is also involved in the production of genetic material. It is crucial that you consume an appropriate amount of zinc: too little can lead to a number of deficiency symptoms, whereas too much can be toxic.
Requirements and safe intakes of zinc differ, depending on your age and gender. However, for convenience, the government has created a single reference value, which allows you to compare the zinc content of different foods. In the United States, the Daily Value, used in nutritional labeling, is based on the highest reference intake of the population and is therefore adequate for anyone. If you are an adult, the Daily Value for zinc is 15 mg, regardless of your gender.
The Recommended Dietary Allowance
The Recommended Daily Allowance, abbreviated RDA, is the amount of zinc that the government has determined appropriate for the vast majority of the population. Nutritionists and dietitians use the RDA when planning institutional feeding programs, and researchers use it to assess the zinc intake of the population. If you are an adult male, your RDA for zinc is set at 15 mg. If you are an adult female, your RDA is set at 12 mg. When pregnant, your RDA increases to 15 mg. If you are breastfeeding, your RDA is 17 mg.
Estimated Average Requirement
The Estimated Average Requirement, abbreviated EAR, is based on experimental studies. The EAR is defined as the amount of zinc that is adequate for 50 percent of the healthy members of a given population sub-group. If you are an adult male, your EAR for zinc is 9.4 mg per day. As an adult female, your EAR for zinc is set at 6.8 mg per day. If you are pregnant, your daily EAR is 9.5 mg. Your EAR for zinc is highest during lactation, when you need an intake of 10.4 mg per day.
Safe Upper Level
The symptoms of zinc toxicity are wide ranging, but usually include nausea and abdominal problems. Chronic ingestion of zinc can also lead to copper deficiency. The Safe Upper Level for zinc supplementation is set at 25 mg a day. You will probably not be able to obtain more than 17 mg a day from food alone, so the maximum amount you can ingest in a day is 42 mg. If you are an adult of average size, you should not experience any adverse effect at this level of intake.