Zinc serves an important role in proper growth. Due to lower bioavailability in plant foods, vegan should increase their zinc absorption by soaking, sprouting, or fermenting grains, legumes, nuts
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What is zinc and why do I need it?
Zinc is an essential mineral that we need to consume through our diet to support metabolic reactions, immune function, and normal growth.
It is involved in synthesizing proteins and DNA, making it critical during pregnancy and early childhood for proper development. In fact, zinc requirements increase by 38% for women who are pregnant and 50% for those who are breastfeeding.
Our bodies cannot store zinc so it must be consumed regularly. It is naturally present in many foods such as grains, legumes, nuts, and seeds.
How much zinc do I need?
The National Academies of Medicine (NAM) has the following Recommended Dietary Allowances (RDA) for daily zinc intake [1].
- Women over the age of 19: 8 mg
- Pregnant women over the age of 19: 11 mg
- Breastfeeding women over the age of 19: 12 mg
The Tolerable Upper Intake Level (UL) for all three of the above groups is 40 mg/day. This refers to intake from fortified foods, water, and supplements, but not to naturally occurring zinc in food [1].
While overt deficiencies are not common, mild deficiencies are more prevalent and often hard to identify because the symptoms vary.
NAM also points out that for strict vegetarians, the dietary zinc requirement may be as much as 50% higher due to lower bioavailability [1]. They do not establish a different recommendation for vegans, but this note is worth keeping in mind.
Can I get enough zinc from plant foods?
The bioavailability of zinc from vegan diets is lower than from nonvegetarian diets, making it a particularly important nutrient to pay attention to [2]. Luckily, plenty of plant-based foods contain high levels of zinc that can meet daily intake needs.
Grains, legumes, nuts, and seeds contain the largest amount of zinc for vegan diets. Here is a list of the top 10 commonly available foods with naturally occurring zinc [3]:
- Wheat germ: 14 mg per cup
- Sesame seeds: 13 mg per cup
- Pumpkin and squash seeds: 10 mg per cup
- Wild rice: 10 mg per cup (dry)
- Peanuts: 9 mg per cup
- Soybeans: 9 mg per cup
- Pine nuts: 9 mg per cup
- Cashews: 8 mg per cup
- Navy beans: 8 mg per cup
- White beans: 7 mg per cup
Keep in mind that for grains, majority of the zinc is stored in the germ and bran so it is important to select whole grains, such as brown rice instead of white rice. Fortified cereals such as Raisin Bran and All-Bran Wheat Flakes are also a great source, containing as much as 15 mg of zinc per serving.
A recent review found that neither vegetarians nor nonvegetarians met the RDA requirements for zinc intake [4]. Interestingly though, no difference was found in blood levels of zinc between the two groups. This study states that further research is needed to identify possible adaptations in zinc absorption for people who consume less of it.
Overall, consuming enough zinc to meet the recommendations, even with the 50% increase for vegans, is doable with considerations for increasing the absorption.
Increasing zinc absorption in plant foods
Phytic acid (known as phytate) is an antioxidant present in many plant foods. While those foods are often health-promoting, there is also concern that phytate can lower mineral absorption [5, 6].
Vegans should implement the following strategies to increase the absorption of zinc from foods [2]:
- Soaking grains, legumes, nuts, and seeds
- Avoiding tea or coffee with meals
- Consuming fermented soy foods such as tempeh
- Sprouting foods (check out this video for tips)
Should I supplement with zinc?
Zinc requirements can be met through a varied diet. However, there are circumstances where a health professional may recommend a supplement, such as for individuals with alcoholism or low caloric intake.
Summary
- Zinc requirements increase by 38% during pregnancy and by 50% for breastfeeding women to support proper growth and development of the baby.
- Grains, legumes, nuts, and seeds provide a good source of zinc.
- Vegans need to pay special attention to improve the absorption of zinc from plant foods. Strategies include soaking, sprouting, fermenting, and avoiding coffee or tea during meals.
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