Zinc Deficiency From a Vegetarian Diet
If you’re a strict vegetarian or vegan, you’re not getting enough zinc from your diet.
This is because the highest amounts of zinc are found in red meat and shellfish.
Another problem is most vegetarians and vegans eat a lot of whole grains and plant proteins. These foods are high in phytic acid, which interferes with zinc absorption. If you are like most vegetarians and vegans, you may need up to 50% more zinc than non-vegetarians.
Why Zinc is so Important
Zinc is an essential trace mineral that’s critical for growth and development. Your body also needs zinc for a healthy immune system, healthy skin, reproduction, blood clotting, vision, taste, smell, insulin and thyroid function, and to fight infections.
“The light-headed feeling of detachment that enshrouds some vegetarians can be caused by hidden Zinc hunger, rather than by some mystical quality of the brown rice or other food consumed.”– Carl C. Pfeiffer, Ph.D., M.D.
How Much Zinc Do You Need
The Recommended Daily Allowance (RDA) depends on your age and sex.
|9-13||8 mg||8 mg|
|14-18||11 mg||9 mg|
|19 +||11 mg||8 mg|
The Daily Value (DV) for zinc is 15 mg for both adults and children that are 4 and older. For vegans and strict vegetarians that eat a lot of fiber, grains, and legumes, the requirement is 50% higher. This is because these foods are high in phytic acid, which interferes with your body’s ability to absorb zinc.
First Signs of a Zinc Deficiency
Symptoms of a mild zinc deficiency include slow wound healing, loss of appetite, and a weakened immune system. Severe zinc deficiencies are rare.
Plant Food Sources With the Highest Amount of Zinc
|Hemp Seeds (1 oz.)||3.2 mg|
|Crimini mushrooms (5 oz.)||1.56 mg|
|Spinach (1 cup)||1.37 mg|
|Pumpkin seeds (1/4 cup)||2.57 mg|
|Sesame seeds (1/4 cup)||2.8 mg|
|Cashews, dry roasted (1 ounce)||1.6 mg|
|Bran Flakes (1 cup)||2.0 mg|
|Wheat Germ (2 tablespoons)||2.7 mg|
|Adzuki Beans||2 mg|
|Granola (1/2 cup)||1.3 mg|
|Tempeh (1/2 cup cooked)||1 mg|
|Tofu (1/2 cup firm)||1 mg|
Some zinc is also found in sea vegetables, summer squash, cheese, asparagus, chard, collard greens, miso, lentils, broccoli, peas, and whole grains.
Whole grains are richer in zinc than refined grains that have not been fortified. This is because most of the zinc is found in the germ and bran portions of the grains. During the milling process these parts of the grain are lost, and so is up to 80% of the zinc.
Most vegetarians and vegans can’t get enough zinc from their diets, so they eat foods fortified with it, or take a zinc supplement.
There are different types of zinc supplements, including zinc gluconate, zinc sulfate, zinc acetate, zinc picolinate, zinc citrate, zinc glycerate, and zinc monomethionine.
There’s no evidence that there’s a difference in zinc absorption or bioavailability between the different types of zinc. But, some are easier on the stomach than others. So if you experience stomach upset, try a different type, like zinc citrate.
Getting enough zinc with plant sources is a challenge. But supplements and fortified foods can easily fill the gap.
Jennifer J. Otten, Jennifer Pitzi Hellwig, Linda D. Meyers, Editors, Dietary Reference Intakes: The Essential Guide to Nutrient Requirements, National Academies Press
Ann Louise Gittleman, Candelora Versace, James Templeton, Your Body Knows Best, (Pocket, 1997)
The world’s healthiest foods, http://www.whfoods.org
King JC, Cousins RJ. Zinc. In: Shils ME, Shike M, Ross AC, Caballero B, Cousins RJ, eds., Modern Nutrition in Health and Disease, 10th ed. Baltimore: Lippincott Williams & Wilkins; 2006:271-285.
Linus Pauling Institute at Ohio State University, Micronutrient Information Center http://lpi.oregonstate.edu/infocenter/minerals/Zinc/
University of Maryland Medical Center, Complementary Medicine