Zinc is a micronutrient that has an important role in our bodies. It helps to resist bacteria and viruses, forms DNA and protein cells, accelerates wound healing and fights against inflammation. Our bodies don’t produce zinc, so we have to make sure to obtain it from nutrition.
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In the general population, zinc deficiency is associated with inadequate dietary intake, as goes with all nutrients. However, the level of zinc bioavailability is also crucial, i.e., how zinc is absorbed in the body and how much of it the body can use. In scientific terms, these are called inhibitors of zinc absorption. Types of food also affect this process in our intestines.
Eat a well-balanced diet and you should be good, right? So, do vegans get enough zinc from the plant-based diet?
Studies have found that vegans can be more susceptible to zinc deficiency. Continue reading to find out what affects the absorption of zinc from plant-based foods, why a deficiency can occur (and how to overcome it), and which foods are high in zinc.
How much zinc should a vegan take daily?
The amount of zinc we need varies based on several factors, such as age, sex, and certain conditions that are related to improper functioning of the intestines or affect the intestinal mucosa (for example, celiac disease, inflammatory bowel disease…).
Pregnant women and nursing mothers also have an increased need for daily zinc intake, as well as the elderly, who most often have increased permeability of the intestinal mucosa, through which nutrients from food pass. Adult men also need more zinc than women.
Vegans also have an increased need for daily zinc intake, mainly because of two factors. Firstly, plant-based foods don’t provide large amounts of zinc compared to animal products, and secondly, the bioavailability of plant sources of zinc is impaired because of the presence of phytates that bind with zinc and reduce absorption in the intestines.
Research was done on comparing zinc levels in vegetarians and omnivores. For example, a 2013 meta-analysis found that vegetarians only have a slightly lower zinc level in their blood compared to those who ate an omnivorous diet. However, there hasn’t been a study that would include people who eat a plant-based diet.
What about vegans? Is there any data on how much zinc should a vegan take daily?
According to science, vegans should consume as much as 50% more zinc than the typical RDI (compared to people who also eat food of animal origin) and 30% more than vegetarians. Accordingly, it means that vegans should include higher intakes of zinc in their diet. In numbers, 15-16 mg/day for adult males and 12 mg for females over 18 years.
|Age||Vegan Male||Vegan Female|
|0 – 6 months||3 mg||3 mg|
|7 – 12 months||4.5 mg||4.5 mg|
|1 – 3 years||4.5 mg||4.5 mg|
|4 – 8 years||7.5 mg||7.5 mg|
|9 – 13 years||12 mg||12 mg|
|14 – 18 years||16.5 mg||13.5 mg|
|19+ year||16.5 mg||12 mg|
The good news is that with a well-planned vegan diet, we can get enough zinc, which our body needs for many cellular processes that affect the growth and development of an organism. Regardless of the diet type, the daily zinc intake is vital because this mineral is not stored in the body. It is also consistently lost through our feces, skin, hair, and semen in males.
What is the bioavailability of zinc?
When talking about the bioavailability of zinc, we mean the percentage of absorption in the body from the food we eat. For example, we can eat foods rich in zinc, but the body uses only a small percentage of it. Absorption is vital because only then zinc is released into the blood and available for systemic circulation and body homeostasis.
The inadequacy of the zinc status is correlated to the poor bioavailability from the consumed diet, whether it is about food that does not contain a lot of zinc or that zinc is not well absorbed from a plant-based diet.
Scientists calculated the zinc bioavailability by studying in vitro cellular intestinal models, since zinc from food is absorbed in the intestine (intestinal epithelium). They found that we absorb between 15 and 35 percent of the zinc we consume. This data tells us that regardless of the diet, not much zinc is absorbed into our body from food.
This percentage can be even lower if we eat food that decreases zinc absorption. It is mainly phytic acid, which is found in legumes, unrefined cereals, seeds, and nuts. If we eat a lot of these foods, the zinc bioavailability can be reduced to 15 percent, thus increasing the risk of suboptimal zinc status.
Some factors increase zinc absorption, and others decrease zinc absorption in the small intestine. Check out which they are:
- Eating plant-based protein improves zinc bioavailability. Ingested zinc in the gastrointestinal tract binds to low molecules of amino acids. These compounds pass more efficiently through the intestinal lumen and enter the bloodstream. Among amino acids, cysteine and methionine are essential for increasing zinc absorption.
- Hydroxy and organic acids (found in citrus fruits, apples, and grapes) enhance zinc absorption.
- Minerals in the form of citrate (can be from food or dietary supplement) positively influence zinc absorption.
- Chemical and physical food processing (especially fermentation, soaking, heating and leavening) increases the bioavailability of zinc. It hydrolyzes phytic acid and consequently reduces or even annuls the negative inhibitory effect that phytates have on the zinc absorption in the body.
- Phytates, compounds naturally present in staple foods like corn, rice and cereals, significantly reduce the zinc absorption from food. Read more about it below.
- Consumption of higher doses of iron (heme-iron and inorganic iron) inhibits zinc absorption. It applies mainly to nutritional supplements and less of iron, which we eat in a meal that also contains zinc. Learn more about iron in my article: Where can vegans get iron.
Do phytates reduce zinc absorption?
Phytates are natural compounds of plants and are present in staple foods, such as legumes, whole grains, corn, rice, cereals, and products made from these foods. They are known for being the main nutritional inhibitors of zinc absorption.
On a vegan diet you might consume a lot of phytates, which may make it harder for you to meet your zinc needs. Meat-based diets typically include fewer phytates. Also, foods of animal origin are more abundant in zinc. Otherwise, phytates can interfere with the absorption of other minerals as well.
Phytates interfere with the absorption of zinc by affecting the intestinal availability of zinc. Our bodies cannot fully break them down. The extent to which phytates interfere with zinc absorption depends on photogenic and macrobiotic phytase.
However, there is a twist. Some studies have found that vegans who consume foods rich in phytates do not have a higher risk of zinc deficiency. I bet you didn’t expect that one. Well, the reason for this lies in the adapted intestinal microbiota, which can break down or degrade phytates into another substance (Myo-inositol phosphate) that enables better absorption of minerals.
How to increase absorption of zinc?
Knowing what reduces the zinc absorption in the body, we can control this process and consequently enhance the bioavailability of zinc and its absorption. It is best to combine the following four methods to increase absorption of zinc:
Decrease the effects of phytates with different methods of processing food
By eliminating the phytates from vegan food sources of zinc, you can significantly increase the amount of zinc absorbed by the body. The best way to do this is to know how to prepare zinc-rich foods that also contain phytates:
- Fermenting foods like tempeh, miso paste,…
- Leavening or adding yeast to whole-grain products
- Soaking food before cooking or eating, like soaking grains, nuts, seeds, beans, whole grains,…
- Using heat like heating, cooking, or toasting legumes, whole grains, nuts, and seeds.
- Sprouting legumes and grains before eating
Opt for unrefined and unprocessed whole-grain products
Zinc in higher concentrations is found in the outer layers of grains. If the grains are refined and processed, the amounts of zinc are significantly reduced. Therefore, it is better to choose minimally refined and unprocessed whole-grain products, such as wholewheat bread, whole meal pasta, brown rice, and rolled oats.
Increase protein intake
Proteins that break down into amino acids increase the zinc absorption from food. The advantage for vegans is that many protein rich plant-based foods are also rich in zinc. For example, nuts and seeds, legumes, tofu, and other soy products. Eating protein-rich plant foods improves your body’s ability to absorb plant sources of zinc.
The simplest solution for optimal zinc intake is to add this mineral in a dietary supplement. However, don’t exaggerate with the doses. The dietary supplement should not contain more than 40 mg of zinc (per daily dose). This is the upper limit. Note that you also get a reasonable amount of zinc from food. If you are taking iron supplements, make sure not to take them with meals that are rich in zinc or together with a zinc supplement.
Visit the NIH Library to learn more about risks and benefits of zinc supplementation.
Which zinc is absorbed the best?
As with all nutrients (vitamins, minerals, trace elements, etc.), our body absorbs zinc best from food. It recognizes it better and can use it for different functions.
Vegans on a diverse and well-planned plant-based diet, including foods rich in phytonutrients, and micro- and macro-nutrients, can meet their zinc needs solely through diet.
According to some studies, zinc from animal-source foods is better absorbed and used in the body. However, research shows that our bodies can adapt to the lower bioavailability of zinc in plant-based diets. This process in the microbiota develops gradually as our bodies increase the efficiency with which they can absorb zinc and reduce losses out of the organism.
It is usually the case that the zinc in food supplements comes from synthetic substances that are not harmful to the body, but are not absorbed in the same way. Zinc supplementation is a good choice if you struggle with deficiency, which you can check by simple blood tests that measure zinc levels in your blood. If zinc intake is sustained at a level that is too high, other problems may occur.
Supplementing with zinc is almost necessary if you are facing potential deficiencies. For example, you have certain conditions in the intestines, you are pregnant, consume highly processed food, or do not include enough whole grains, beans, and nuts in your meals. Supplementing with zinc is also useful when you get sick (colds, viruses…) and need extra support to boost the immune system.
If you decide to take zinc supplementation, you can choose from various forms of zinc. Zinc gluconate, bis-glycinate and picolinate are considered to be the most bio-available forms, which are well absorbed by the body. Avoid zinc oxide, which is a cheap form and does not absorb well.
What vegan foods are high in zinc? Top 7 plant sources of zinc
Meat (also seafood) and dairy products have the highest zinc content, but as already mentioned, that does not mean that you can’t get enough zinc from vegan foods. You can meet your recommended daily intake with these seven plant sources of zinc:
- Legumes: especially lentils, beans, and chickpeas. These are also high in protein, yet on the other hand, they contain phytates, which you can reduce with cooking, sprouting, or fermenting.
- Nuts: are also high in protein and fiber. Cashews contain the most zinc, followed by walnuts.
- Grains: mostly quinoa and brown rice.
- Seeds: hemp and pumpkin seeds are rich in zinc, followed by sesame and sunflower seeds.
- Oats: are a good source of zinc. They contain phytates, but you can eliminate them by soaking oats.
- Tofu: made of soy is rich in protein and minerals, such as zinc.
- Tempeh: is also rich in protein and zinc.
Try to avoid processed foods as much as you can, because there’s not a lot of zinc in there. Zinc is not stored in the body, so you have to include it in your daily diet.
Are zinc supplements vegan?
Zinc is derived from synthetic sources and thus cannot originate from substances of animal origin. But check to see if non-vegan ingredients can be added to zinc. If you decide to take a multivitamin that also includes zinc, check the dose, as it may be that the zinc dosage is too low for daily needs, or that zinc is in combination with vitamin D from lanolin, a substance from sheep’s wool.
It is also essential whether the brand provides certification, for example, a Peta-approved or Vegetarian Society certificate. Also, pay attention to auxiliary substances, such as lactose, or synthetic substances, such as artificial colors, flavors, fragrances, and preservatives. It is best to choose vegetable capsules made from cellulose rather than those made from animal gelatin.
There is no need to become zinc deficient on a vegan diet, as there are plenty of plant sources of zinc, such as legumes, nuts, soy products, and whole grains. If you do not eat plenty of zinc-rich foods, you can add zinc. For optimal uptake, use modern food processing and cooking methods to eliminate phytates. Also, make sure to include enough protein to help with the absorption of zinc.
Zinc is a mineral which should not be left out of any diet. This is a very important nutrient for immune system function and infection control. It metabolizes other nutrients in the body, plays a major role in fertility, and cares for healthy hair and skin.