Plant-Based Diets and Iron Deficiency: What You Need to Know

By: Anna Clancy

Disclaimer: The nutrition and health discussion found in this story is not intended to be a replacement for health or medical advice. Always consult with a licensed healthcare provider for any diet-related concerns. The contributing author is a Point Loma Nazarene University Dietetics student.

The increasing number of individuals following a plant-based diet has put a spotlight on the importance of consuming and absorbing enough iron.

The National Institutes of Health (NIH) reports that the number of Americans following a plant-based diet increased by 600% from 2014 to 2018. Plant-based diets include both vegetarian and vegan diets, with their followers citing a variety of reasons for this dietary change — from improving health and protecting the environment to standing up for animal welfare. 

Professor and Point Loma Nazarene University Director of Dietetics Cindy Swann said for those pursuing or considering a plant-based diet, it’s important to understand the extra challenges of absorbing enough iron. 

“While the iron found in plant-based foods is certainly absorbed in the body, it’s not as effectively absorbed as the iron found in animal sources,” Swann said.

According to the Harvard T.H. Chan School of Public Health, the iron in foods can be found in two forms ‒ heme and non-heme. Heme iron is only found in animal sources, such as red meat, poultry and seafood, while non-heme iron is from plant sources, such as legumes, tofu, dark leafy greens and iron-fortified products  

“It is generally accepted that 10% to 35% of heme iron is absorbed in the body whereas non-heme iron is only absorbed at a rate of 2% to 10%,” Swann said. “While someone on a plant-based diet may consume a similar amount of iron as someone who eats meat, the non-heme iron may not be as effectively absorbed, resulting in an increased risk for iron deficiency.”

PLNU Wellness Center Dietitian Carrie Gunn said iron is an essential mineral to consume in adequate amounts because it maintains a healthy red blood cell count in the body. 

“Iron affects our energy levels and not having enough can result in fatigue, dizziness and headaches, but can also lead to more serious complications if not corrected,” Gunn said. “As a college student, the last thing you need is to feel fatigued with low energy and a reduced ability to think clearly while walking around this large campus.”

Fourth-year dietetics major Caitlin Arakaki said she is familiar with the challenges of getting enough iron on a plant-based diet. 

“In the past, I have struggled on and off with lightheadedness and feeling like I had zero energy, which I eventually found out was related to iron deficiency as evidenced by low ferritin levels in my blood,” Arakaki said. 

Swann said despite the increased challenges faced by plant-based eaters, there are ways to support adequate iron absorption. 

“One of the simplest methods is to consume vitamin C-rich foods in tandem with iron-rich ones, since vitamin C enhances the absorption of iron,” Swann said. “That might look like having iron-fortified cereal with cantaloupe or a lentil stew with bell peppers and tomatoes.” 

Gunn added that it’s also important to be aware of foods that can inhibit the absorption of iron.

“One recommendation is to refrain from drinking tea, coffee or wine alongside your iron-rich meal, since these beverages contain tannins, a group of compounds that can interfere with iron absorption,” Gunn said. “Another compound to watch is phytic acid – found in whole grains, legumes and seeds, which is why it’s best to eat these foods alongside vitamin C to increase iron absorption.”

Swann said she recommends that plant-based eaters aim to consume greater than the recommended daily amount of iron, due to the increased challenges of absorption. 

The Academy of Nutrition and Dietetics states that the Recommended Dietary Allowance (RDA) for iron is eight milligrams per day for men and postmenopausal women and 18 milligrams per day for women of reproductive age. 

Arakaki said her struggle with iron deficiency empowered her to find ways to modify her diet to support her needs.

“Now if I’m having a vegetarian burrito bowl, I include bell peppers and spinach for more vitamin C and add larger portions of black beans,” Arakaki said.

 Gunn said she encourages students to make an appointment with her if they are concerned about how their diet might be impacting their ability to get enough nutrients.