CHAPTER 5 
Complete Nutrition
SOME PEOPLE WONDER IF A VEGAN DIET WILL GIVE THEM all the nutrition they need. Actually, a plant-based diet provides better nutrition than a diet including meat and dairy products. Harvard researchers developed a system for rating the healthfulness of various eating patterns, called the Alternate Healthy Eating Index. It turns out that vegan diets score much better than diets including meat and dairy products. Surprised? Well, meat is low in many vitamins and minerals. It has no vitamin C and no fiber at all, and it is high in saturated (“bad”) fat and cholesterol. Yes, meat does have protein and iron, but so do plants, in more healthful forms. Similarly, dairy products have lots of fat, protein, and sugar and miss the vitamins that are in vegetables, fruits, and beans.
In our research studies, we track what happens when people adopt plant-based diets. Good news: Their nutrition improves dramatically.15 Plant-based foods provide the right amount of protein, a better quality of fat, abundant healthful carbohydrates for energy, fiber for healthy digestion and cancer prevention, and vitamins and minerals in far better proportions than are found in animal products.
Even so, you might be wondering about getting adequate protein, calcium, and other nutrients. So let’s take a quick look at the details.
Okay, So Where Do You Get Your Protein?
According to the US government, women need about 46 grams of protein per day. Men need about 56 grams. The actual amounts needed are likely less; these numbers include a margin for safety.
If you were to eat nothing but broccoli for a day, you would get 146 grams of protein on a typical 2,000-calorie diet. The next day, if you were to eat nothing but lentils, you would get 157 grams of protein. Pinto beans? 186 grams. If you were to eat only oatmeal, you would get 62 grams of pure protein. Of course, I’m not suggesting that you actually eat just one food in a day—this is just an illustration—but the point is that plants have lots of protein. You are probably aware that there is a lot of protein in soy products; true enough, but vegetables and grains have protein, too.
So, plants have protein. “But is it complete protein?” you may ask. Proteins are actually long chains of amino acids, joined together like beads on a necklace. Complete protein is protein that has all the amino acids you need. Decades ago, some people imagined that one had to carefully combine various plants to get “complete protein.” But it turns out that any normal variety of plant-based foods brings you all the amino acids you need. In its official position paper, the Academy of Nutrition and Dietetics says, “Protein needs at all ages, including those for athletes, are well achieved by balanced vegetarian diets.”16
Calcium Straight from the Source
Where do you get calcium without dairy products? Well, cows don’t actually make calcium at all. Calcium comes from the Earth. Green vegetables pull calcium from the soil through their roots, and it ends up in their leaves. When cows eat grass, calcium passes into their milk. You can get the calcium you need directly from plants, too—hopefully not grass! But there is abundant calcium in broccoli, Brussels sprouts, kale, collards, and other green leafy vegetables. In fact, their calcium is actually more absorbable than that in milk. An exception is spinach, which is a rather selfish vegetable; it will not release much of its calcium. But most green vegetables provide plenty of highly absorbable calcium. It pays to emphasize them in your routine. Beans provide calcium, too, as do squash, sweet potatoes, tofu, figs, oranges, and raisins, among many other foods. If you are looking for extra calcium, calcium-fortified nondairy milks (e.g., calcium-fortified soy milk, almond milk, and rice milk) are loaded with it.
Iron, the Healthy Way
You need iron to make the hemoglobin that your blood cells use to transport oxygen, and the best sources are green leafy vegetables and beans. In fact, in our research studies, people adopting a vegan diet often get slightly more iron than they did on a meat-and-dairy diet, thanks to the iron in greens and beans.
In the 1950s, the idea was “the more iron, the better.” Television shows advertised the iron supplement Geritol as the answer to “tired blood.” But soon it became clear that extra iron is dangerous. If there is too much iron in your body, it can spark the production of dangerous free radicals, which can harm the heart and brain and contribute to the aging process. So while the body needs a trace of iron, overdoing it is risky.
Plants have a healthful form of iron, called nonheme iron, that is more absorbable when your body is low in iron and less absorbable when your body already has plenty on board. That way, you get the iron you need without overdosing. Meat has a form of iron called heme iron, which is highly absorbed whether you need it or not. That can lead to iron overload.
Bottom line: Greens and beans have the iron you need in the healthiest possible form.
Vitamin B12: Easy, but Essential
Vitamin B12 is essential for healthy nerves and healthy blood cells. But it is not made by plants or animals. It is made by bacteria. Some people speculate that, before the advent of modern hygiene, the traces of bacteria in the soil, on vegetables, on our fingers, and in our mouths gave us the traces of B12 we needed. Whether that is true or not, modern hygiene has eliminated that possibility.
Meat and dairy products contain traces of B12 because an animal’s intestinal tract harbors bacteria that produce it. But those are hardly healthful sources because along with it come cholesterol, “bad” fat, and other problems. In addition, many people have trouble absorbing B12 from animal products. Many older people do not produce enough stomach acid to separate the B12 from the protein it is bound to, and common medications (e.g., metformin, often used to treat type 2 diabetes, and acid blockers) interfere with its absorption. So, even while eating animal products, they do not absorb adequate B12. A vegan diet, of course, does not include meat or dairy products.
The simplest thing to do is to take a vitamin B12 supplement. Every drugstore and natural food store sells them. Adults need 2.4 micrograms per day, according to the US government, and all common brands have more than that (some have much more). So pick up any common brand with a modest dose (e.g., 50 micrograms) and take it daily. You will see it in two forms, cyanocobalamin and methylcobalamin. Both are effective.
On a vegan diet, it is essential to add a source of B12. Don’t skip this. A B12 deficiency can take years to develop, but the first sign can be nerve symptoms that are irreversible. 
Vitamin D
Vitamin D is produced by sunlight on your skin. It helps you absorb calcium from the foods you eat and also helps protect against cancer. About twenty minutes of sunlight on your face and arms a few times each week gives you the vitamin D you need. But if you are not getting regular sun exposure, or if you use a sunscreen, a vitamin D supplement can be very helpful. A daily dose of 2,000 international units is considered safe.
Do I Really Need to Take Supplements?
Some people resist taking a supplement of vitamin B12 or D because “nature ought to provide the nutrition we need.” True enough. But you don’t live in nature. You live in New Jersey. Or maybe Portland or Glasgow or Reykjavík or Oslo or Tierra del Fuego or somewhere else where there is not enough sunlight, in all likelihood. Had our forebears had the good judgment to remain in sunny eastern Africa, we would have gotten all the vitamin D anyone could ever want.
Similarly, it may well be that in our less-than-hygienic past, bacterially produced B12 was more abundant than it is today. It’s also possible that when we ate more healthfully, we were able to absorb the B12 produced by our own gut bacteria. Who knows? But because humans have moved away from nature, supplements of vitamin B12 and (for those not getting regular sunlight) vitamin D play important roles.
Omega-3s
Although some fats are risky—saturated fats raise cholesterol, for example—your body does need traces of good fats. One in particular is called ALA, or alpha-linolenic acid. The name is not important, though what is important is that it is a healthful omega-3 fatty acid that your body will lengthen into another omega-3, called DHA (docosahexaenoic acid), that your brain uses. Where do you find it? There are ALA traces in green leafy vegetables, fruits, and beans, and much larger amounts in walnuts and various seeds. If these foods are in your routine, you’ll get the healthy fats your body needs.
Some people use omega-3 supplements. Some of these supplements are vegan; others come from fish oil. Their benefit has not yet been proven. A potential disadvantage of these products is that they can make bleeding more of a problem. That is, they make it harder to stop bleeding when you have a cut or have surgery, and internal bleeding may be more likely. So my suggestion is to take advantage of the traces of healthful fats in green leafy vegetables, fruits, and beans and to minimize the use of competing fats and oils. Hopefully, further research will clarify what, if any, role there may be for omega-3 supplements.
A vegan diet that relies primarily on whole foods will naturally give you great nutrition. Everyone also needs vitamin B12, and if you’re not getting sunlight, you’ll need a vitamin D supplement, too. But that is about it. It pays to favor green leafy vegetables for calcium. For most people, there is no need for a multivitamin or other vitamin supplements (unless your caregiver has specifically called for them). You’ll get the nutrition you need from food.