Plant-Based Nutrition

By Jack Norris, Registered Dietitian

Generally, research on human populations has shown that the higher a percentage of plant foods an individual eats, the lower their risk is for obesity, high cholesterol, high blood pressure, type 2 diabetes, heart disease, and cancer.

While vegetarians and vegans have lower rates of many of the major chronic diseases, there are some nutrients they should make sure they’re obtaining. Below are some general guidelines and you can find more specific amounts for different age groups at VeganHealth.org. The precise amounts aren’t important to reach each day—rather making sure you come close on most days is what’s important.

Protein

Protein meme

It’s easy to get enough protein on a plant-based diet when you include a few servings of legumes each day. Legumes include beans (garbanzo, kidney, pinto, hummus, refried, etc.), peas (green, split, black-eyed), lentils, peanuts, and soybeans (tempeh, tofu, soy milk, soy meats, edamame, etc.). Other plant foods high in protein are quinoa, seitan, nuts, and pumpkin seeds.

Vitamin B12

Vitamin B12 meme

Vitamin B12 is the one nutrient not found in plant foods in any reliable amount. Make sure you get a reliable supply of B12 as described above.

Calcium

Calcium meme

Adults need 1,000 mg of calcium per day. Eat at least three servings per day of the high-calcium foods in the meme above or take a supplement of 250-300 mg/day. A serving of greens is 1/2 cup cooked or 1 cup raw.

Iron

Iron meme

Some women of child-bearing age, especially endurance runners, can become deficient in iron. Plant foods contain ample iron, but it’s harder to absorb without a source of vitamin C at the same time. If you’re prone to iron deficiency, mixing high-iron foods (in meme above) and vitamin C (in meme below), and avoiding coffee and tea at meals, will maximize absorption.
Vitamin C meme

Zinc

Zinc meme

Zinc is found in tofu, beans, nuts, and oatmeal. Most vegans get about the RDA for zinc but some fall short. Zinc plays a role in the building and repair of muscle tissue and preventing colds. A modest supplement of about 10 mg per day might benefit some vegans, especially strength athletes.

Vitamin A

Vitamin A meme

Vitamin A is made from beta-carotene. Eat some of the above foods or drink carrot juice every day.

Vitamin D

Sunlight provides vitamin D if the upper body (or the equivalent amount of skin) is exposed a few times a week during mid-day; otherwise a supplement of 600-1,000 IU (15-25 µg) per day is recommended. Deficiency results in fatigue and bone pain.

Iodine

To ensure adequate iodine intake, vegans should eat seaweed, iodized salt, or take an iodine supplement of 75-150 μg, two to three times per week.

Omega-3

Eat a serving of walnuts, canola oil, flaxseeds, hemp seeds, or chia seeds (or their oils) daily or take a vegan omega-3 supplement.

More Info

VeganHealth.org is a website dedicated to giving vegans the most accurate nutrition information possible. It is run by Jack Norris, Registered Dietitian who is also the Executive Director of Vegan Outreach and has been vegan since 1988.

The most important articles for new or aspiring vegans are:

9 thoughts on “Plant-Based Nutrition

  1. It’s always great to see rational, fact-based responses to the emotional and often false beliefs that seem to permeate our culture.

    One point that I think is lost here is one of simple practicality: you honestly do not need to worry about getting enough of any one nutrient or another as long as you are eating a reasonably varied diet and getting enough calories.

    More to the point, how many people in this country are diagnosed with a deficiency in any one of these nutrients? Vanishingly small, I’d bet and it pales in comparison to those diagnosed with heart disease, diabetes, hypertension, strokes, or any of the other maladies stemming from consuming animals.

    1. Hi Dave–

      Thank you for your comment on this and I completely agree that a meat-based diet is more likely to lead to some of the more common degenerative diseases and in that sense, meat-eaters have more to worry about than do vegans. However, the nutrients I put together that vegans should pay attention to are either nutrients that won’t necessarily be covered by simply eating a varied diet and do cause problems when they aren’t, or nutrients that can be a problem to a small, but not insignificant amount of vegans. There is no reason to panic, but you should go down the list and read them and make sure you’re covering your bases.

  2. Hi Jack,
    I’ve been a vegan for just over a year. I’ve had some hiccups along the way – feeling rundown, the reappearance of some patches of psoriasis on my elbows that had disappeared since childhood – so I take low supplements of B12, Zinc, and I was taking a supplement of Iodine (just over 100% RDA). I’ve always had really clear skin but now I have what looks like the start of acne. I stopped taking the iodine because I think it dates from when I started taking that. (I was taking B12 from the start, but Iodine only the past few months.)
    – If it is the Iodine, do you know how long should it take to clear up?
    – Is there anything apart from B12 and Iodine that can cause this, in a vegan diet? I do eat a lot of soy in the form of yoghurt, milk, tofu and edamame.
    – Could it be the B12, even though I was taking B12 for months before my skin got bad?
    Thanks in advance for any advice you can give me.

    1. Sheena–

      Small amounts of B12 shouldn’t cause acne. How much are you taking?

      I see there’s a lot on the internet saying iodine can aggravate acne, but I didn’t find anything from a reliable source.

      I’m wondering if you’re getting enough vitamin D? Do you pay attention to that in any way?

      1. Hi Jack,

        For B12, I take:
        – about 4mcg of B12 in syrup, most days.
        – nutritional yeast (2.2mcg per 5g) – probably about 2 tbsp a day.
        – soy yogurt – (.38mcg B12 per 100g) – maybe 200g-300g per day. (I eat a lot of yogurt).
        – margarine – (.5mcg per 10g) – maybe 30g per day?
        – soy milk – (.38mcg per 100ml) – about 250 ml most days.

        Vitamin D:
        Occasionally take a 10 mcg tablet but not really that regularly. I was taking them regularly when my skin got bad and I actually stopped taking them along with the iodine. I get:
        – yogurt – (.75mcg of D2 per 100g) – 200-300g a day.
        – margarine – (.8mcg D2 per 10g) – 30g/day.
        – soy milk (~1mcg of D2 per 100ml – I make porridge half and half with soy milk and a soy milk for kids that has twice the vitamin D in it, it averages just over 1 mcg) – 250ml/day.

        So, now you say it, I think I’m getting about 300% my RDA of B12. Would that be enough to cause it?

        1. Hi Sheena–

          It’s extremely unlikely for 300% of the RDA of B12 to cause skin problems. Doses that do that tend to be more in the realm of 400 times the RDA (which is more like 2,000%).

          Psoriasis is not likely to be diet-related. Mayo Clinic says that exposing the skin to small amounts of sunlight can help as can some topical vitamin D ointment, that’s why I though perhaps it could be related to a significant vitamin D deficiency but that is more theoretical than evidence-based. It’s not uncommon to get vitamin D levels tested and I recommend that vegans do that every few years just to make sure they’re getting enough.

          Mayo Clinic info: http://www.mayoclinic.org/diseases-conditions/psoriasis/basics/definition/con-20030838

          Good luck and I hope you find a solution!

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