Zinc is best absorbed when taken on an empty stomach, in the morning, or about 30 minutes to one hour before breakfast. However, people who experience severe nausea or stomach upset may have to take zinc with food to reduce the risk of side effects.
Zinc can be taken at any time of day, with or without food. However, taking zinc before breakfast may improve its absorption.
A 2021 study found that taking zinc before breakfast resulted in about 18 times more zinc in the blood than taking it with food.
Other research suggests that zinc is about 60-70% absorbed when taken with a liquid meal like a protein shake, on an empty stomach. However, absorption is significantly lower, about 16-50%, when taken with normal meals.
There are times when zinc may be more suitable for use in the evening. If you are taking zinc for long-term benefits, such as building immunity, it may be best to take it consistently at the same time each day.
Zinc may be taken at different times of the day depending on the health condition you need to manage:
- Common cold: Zinc supplements may work better at reducing the severity and length of cold symptoms when taken within 24 hours of the first sign of cold symptoms.
- Immune support: Taking zinc on an empty stomach or just before breakfast can improve its absorption. However, if taking zinc on an empty stomach causes nausea or vomiting, it may help to take it a few hours after eating.
- Sleep quality: For improving sleep quality, zinc may be taken in the morning or evening, with or without breakfast. However, some studies recommend taking zinc about one hour before bedtime to improve sleep.
- Skin health and wound healing: For wound healing, zinc is best taken in the morning, before breakfast, when absorption is optimal. For acne, some research suggests that because the skin may be more permeable and inflammation can increase at night, applying treatments in the evening may improve their effectiveness. So, taking zinc in the evening may work better for treating acne.
In addition to timing, other factors can affect how much zinc is absorbed. These include:
- The type of food you eat with zinc: Some foods may help improve the absorption of zinc supplements. Zinc absorption has been found to be substantially higher when taken with animal protein than with plant-based protein.
- Other supplements you’re taking: Taking iron supplements at the same time as zinc has been found to reduce zinc absorption. High amounts of calcium and phosphorus can also lower zinc’s absorption.
- How long you’ve been taking zinc: Some studies have found that, over time, daily zinc supplementation may decrease absorption. This occurs because the body reduces the number of zinc transporters in response to consistently high zinc intake.
- The form of zinc you choose: Zinc supplements are available in different forms, including zinc glycinate, aspartate, oxide, chloride, sulfate, and acetate. Some studies found that zinc glycinate was better absorbed than other forms of zinc, while zinc oxide was the least well absorbed.
