Vegan Zinc – Sources, Absorption, and Deficiency
July 31, 2020
Why zinc is important for vegans
Zinc is an essential nutrient to consider when following a vegan or vegetarian diet. It is a mineral that is distributed throughout all our body tissues and fluids. It is necessary for our body to perform a variety of important functions (1).
Some of these include:
- Immune support and wound healing
- Regulation of gene expression and DNA synthesis
- Supports normal growth and development during childhood, adolescence, and pregnancy
Zinc requirements for vegans
Those following a vegetarian or vegan diet have higher requirements for certain vitamins and minerals than those specified for the general healthy population. These include the minerals iron and zinc.
Zinc is one of these nutrients as plant-based sources have a lower bioavailability than animal-based sources such as red meat and dairy. In other words, it is harder for our bodies to absorb this nutrient from plant-based foods.
It is recommended that those following a vegan/vegetarian or predominantly plant-based diet consume 150% of the recommended daily intake for the general population to ensure requirements are met.
Below is a summary of the daily requirements for vegetarians/vegans based on 150% of the values provided in the Nutrient Reference Values for Australians and New Zealanders(2).
There is no difference in the RDI between older adults (70 years+) and those in their early stages of adulthood. See zinc requirements for those following a non-vegetarian or vegan diet here (4).
Best vegan sources of zinc
Zinc is present in a variety of plant-based foods. A well-planned vegetarian or vegan diet is more than adequate to meet your requirements.
It can be found in high concentrations in the outer layers of grains. As such, the best plant-based sources are minimally refined wholegrain products such as rolled oats, brown rice, and wholegrain bread and cereals.
Vegan zinc sources include nuts and seeds, legumes, soy products such as tofu and fortified breakfast cereals(1).
The following table lists the amounts found in different plant-based foods (3):
It is recommended that you include a variety of these foods in your diet on a daily basis.
This may look like:
½ cup oats + 1 cup soymilk + 30g pumpkin seeds + berries
2 slices wholegrain bread + 2 tbsp hummus + ½ cup salad + 15g sundried tomato + 100g sliced tempeh
Tofu stir fry (with 150g tofu, 30g cashews, 2 cups mixed vegetables) + ½ cup brown rice
30g pecans, 1 apple, hot chocolate (2tbsp cocoa, 1cup soymilk, 1tsp sugar), 4 wholegrain crackers + 2tbsp tahini + tomato
TOTAL: 21.5mg total
Optimising zinc absorption
Plant-based sources of zinc are not as readily absorbed by the body. This is due to the presence of inhibiting compounds in foods that reduce absorption.
The main inhibitors are phytates which are commonly found in wholegrains and legumes.
This effect can be overcome by food-processing techniques such as the fermentation of whole grains and soaking legumes and sprouting seeds and grains.
Additionally, taking iron supplements close to meals can also inhibit the absorption of zinc as the two nutrients compete for uptake (1,4).
Foods that contain high amounts of protein are also a good choice to consider as protein binds to zinc and increase zinc absorption.
Some simple ways to improve vegan zinc absorption include:
- Opting for yeast-leavened or sourdough bread
Pre-soak and rinse legumes before cooking
Opting for sprouted grains and seeds
Consume iron supplements away from meals
Include foods high in both zinc and protein such as legumes, tofu, tempeh and nuts
Signs of a zinc deficiency
Cases of deficiencies are rare in developed countries due to our abundance of access to zinc-rich foods however they are still possible.
The main reasons for developing a deficiency include poor dietary availability paired with an increased requirement during periods of growth and development or periods of stress, infection and acute trauma(2).
Signs of a deficiency to look out for include:
Reduced growth rate in children
Suboptimal pregnancy outcomes
Increased susceptibility to illness and infections
Poor wound healing
Impaired taste perception
Is being vegan a risk factor for developing a zinc deficiency?
No, despite differences in food choices, vegetarians and vegans tend to have similar blood levels of zinc to non-vegetarians.
Over time, the body is able to adapt to the lower bioavailability of zinc in plant-based diets by increasing the efficiency in which it is able to absorb this mineral and reducing losses out of the body. Therefore, those following a plant-based diet are at no greater risk (1).
If you are concerned you may have a zinc deficiency it is important to discuss any concerns with your GP.
Should vegans supplement zinc?
It is absolutely possible to meet your requirements from solely food sources when following a plant-based or vegan diet. This is always preferred over supplement use.
Whilst there is no evidence of adverse effects from consuming high amounts of zinc naturally occurring in food, excess zinc intake from long term high doses of zinc supplements may result in negative side effects. This includes negatively affecting the immune system , lowering HDL (also known as good cholesterol) levels and copper deficiency.
There are a variety of forms of zinc available in supplements. These include zinc acetate, sulfate, picolinate, monomethionine, gluconate, glycinate, orotate and citrate.
There is an upper limit of total zinc intake of 40mg/day from food and supplements (including fortified foods) and any supplementation should proceed with caution(2).
To reduce the risk of having excess zinc supplementation, it is important to seek medical advice from your GP before commencing and supplements.
If you’re following a plant-based or vegan diet and want to make sure you’re meeting all your nutritional needs, take control and apply to work with one of our expert plant-based dietitians. .
This blog was co-written by student dietitian by Georgia D’Andrea. You can connect with Georgia on Linkedin.