Vegetarians are constantly being warned that they should take care to get enough protein. Vegans also get admonished with threats about calcium and vitamin B12 deficiencies. While these nutrients are important, they really aren’t that difficult to get on a vegetarian or vegan diet.
So long as vegetarians are eating a variety of protein, they should have no problem getting enough of all their amino acids. With the help of fortified soy milk, calcium doesn’t have to be a problem. And, for B12, there are supplements available.
However, there are some overlooked nutrients that vegetarians may need to be worrying about.
According to a report from the World Health Organization, the global prevalence of zinc deficiency is 31%! In high-income countries such as the US and UK, the incidence is much lower at an estimated 4-7%. However, this is still a high prevalence of deficiency. So, everyone (not just vegetarians) would do good to eat more zinc-rich foods.
Unfortunately for vegetarians, plant-based foods which are high in zinc also have high levels of phytic acid. Phytic acid blocks the absorption of zinc. Vegetarians may need to consume as much as 50% more than the RDA for zinc in order to get adequate amounts. Good vegetarian sources of zinc include nuts, seeds, bran, and wild rice.
Docosahexaenoic acid, or DHA, is a fatty acid which is incredibly important for cell health and nervous system function. Our bodies can make DHA out of Omega 3 fatty acids. So, one would think that eating more Omega 3 foods (such as flax) would help us get enough DHA. Unfortunately, it isn’t as simple as this.
The body is not very good at turning Omega 3 into DHA. Only about 9% of Omega 3 gets turned into DHA in women. With men, the rate is much lower at 0-4%. Luckily, there are DHA supplements available for vegetarians. Vegetarians can also get DHA in their diet by eating algae and some types of fungi.
Iron deficiency is one of the leading global health problems which, according to one report, accounts for 841,000 deaths each year. 1.4% of these deaths are in North America.
While iron deficiency is prevalent amongst all populations, vegetarians are particularly at risk. The reason is because non-heme iron (iron from plant sources) has a much lower absorption rate than heme iron (iron from animal sources). Thus, the Institute of Medicine recommends that vegetarians consume nearly twice the RDA for iron.
The RDA for iron is 15-18mg daily for adult women and 8-11mg for adult men. That means that vegetarian women would have to eat about 2 cups of cooked spinach, 1 cup of beans, 1 cup of bran, and 2 cups of quinoa daily to meet iron RDAs.
Luckily, there are some ways to increase the body’s absorption of non-heme iron, such as by consuming vitamin C with iron foods, or fermenting them.
If you are a vegetarian and aren’t eating iodized salt, then you may not be getting enough iodine. A study published in the Annuals of Nutrition & Metabolism found that 25% of vegetarians and 80% of vegans are not getting enough iodine. These findings are supported by numerous other studies as well.
While mineral salts do contain some naturally-occurring iodine, it is typically only in trace amounts. Unless you are buying a mineral salt which lists its measured mineral contents on the label, you should not rely on these salts for your iodine. Instead, get a salt fortified with iodine or start consuming more seaweed, a natural source of iodine.
It only takes about 20 minutes of sun exposure daily to get enough vitamin D. But, since many Westerners spend most of their time indoors, vitamin D deficiency has become pandemic. One study found that the prevalence of vitamin D deficiency in US adults was 41.6%. Some foods do contain vitamin D, but very few of these are plant-based. All of us (not just vegetarians) should make a point to spend more time in direct sunlight (without sun block on!) to get enough vitamin D. If tests show that vitamin D levels are low, then a supplement may be in order.