Vegan for Life (12 page)

There isn’t much information about the vitamin K intake of vegetarians or vegans, but what we know suggests that people eating plant-based diets get plenty. So why have we singled it out for discussion? The answer has to do with claims that have been made about vitamin K from those who question the adequacy of vegan diets.

The term “vitamin K” actually refers to two slightly different compounds with vitamin K activity. One, called phylloquinone or vitamin K
₁
, is found in both plant and animal foods. The other, menaquinone or vitamin K
₂
, is produced by bacteria and found in animal foods; plants don’t contain any. While some have claimed that vitamin K
₂
is a separate vitamin with its own role in the body, no research supports this.

A study comparing blood-clotting rates (a measure of vitamin K activity) showed no difference between vegans and meat-eaters, which suggests that vegans are getting plenty of vitamin K.
¹⁰
And studies have shown that vitamin K
₁
supplements are effective in older people for reducing bone fracture risk.

Since bacteria in the colon produces vitamin K
₂
, vegans are getting this form of the vitamin anyway. Finally, the Institute of Medicine has not established any specific recommendations for vitamin K
₂
. We can say with assurance that vitamin K
₂
is not a separate nutrient, and vegans do not need it in their diet.

Over the years, there has been some discussion about riboflavin (vitamin B
₂
) in a vegan diet since the main source of this nutrient in American diets is milk. But while riboflavin is found in only small amounts in many plant foods, a varied diet of grains, legumes, and vegetables provides plenty. Soyfoods are a particularly good source of riboflavin. We don’t have a great deal of information about vegan intake, but the few studies that have been done show that vegans meet the RDA for riboflavin. Choosing soy (or other plant) milks that are fortified with this nutrient can provide extra insurance, but we don’t think that vegans need to worry about riboflavin. We’ve listed the riboflavin content of plant foods on page 77.

Both vegans and omnivores need to pay attention to the mineral potassium. Since legumes are a good source of this nutrient, vegans tend to have somewhat higher intakes than meat-eaters. But it’s not easy for anyone to meet the recommended daily intake of potassium, which is 4,700 milligrams, without a bit of planning. Including plenty of vegetables in your diet is the easiest way to meet potassium needs, but it’s important to choose those that are especially potassium-rich. Best sources are certain leafy greens (beet greens, spinach, and Swiss chard), cooked tomato products and tomato juice, orange juice, sea vegetables, bananas, and legumes. The table on page 78 shows the best sources of potassium for vegans.

The mineral selenium is the only other nutrient that may be an issue for some vegans. It depends on where you live—or where your food comes from—since the amount of selenium in plant foods is dependent on the amount in the soil where the foods are grown. Evidence suggests that vegans in the United States and Canada get enough selenium. In parts of northern Europe, the selenium content of the soil is fairly low, however, and vegans may need to supplement. The table on page 79 reflects selenium content of plant foods grown in the United States.

It’s good to know the different sources of individual nutrients and how to meet your needs for each one. But planning a healthy diet by tracking intake of individual nutrients can quickly become overwhelming and confusing. And it’s not necessary for vegans or anyone else to do so. In the next chapter, we’ll provide simple guidelines for planning menus that bring together the information we’ve talked about so far. It’s the Vegan Food Guide—and it makes planning vegan diets a breeze.

F
ood guides have been a part of nutrition education in the United States for nearly one hundred years. They’ve come a long way too. The first one, published in 1916, had five food groups: fruits and vegetables; meat, fish, and milk; cereals; simple sweets; and butter and wholesome fats. It was produced by the United States Department of Agriculture (USDA), the same group that produces the food guide pyramid for Americans today.

While pressure from agriculture and the food industry shapes current food guides and keeps them friendly to animal foods, the trend has been toward a greater emphasis on plant foods. Even so, government food guides are not especially useful for vegetarians, and they are all but useless for vegans. Therefore we need to create our own.

The food guide in this chapter is not the final word on planning a healthy vegan diet. No single food guide represents the only way to meet nutrient needs. And you don’t need to follow these guidelines with meticulous attention every day. You won’t keel over and die if one day you have only four servings of grains!

This is meant to point you towards a diet that is based on a variety of whole grains, legumes, nuts, fruits, and vegetables. The guide doesn’t include items like chocolate chip cookies, potato chips, and wine. But that doesn’t mean you can’t have them. They just don’t fit into the food groups that should be at the center of your diet.

To translate nutrition information into simple menu-planning guidelines, we’ve divided foods into the following groups:

These foods are high in fiber, and provide protein, iron, zinc, and B vitamins. We’ve included starchy vegetables like potatoes and sweet potatoes because their calorie content and nutrient profiles are similar to those of grains. Although it’s always a good idea to choose whole grains, products like fortified cereals can sometimes make important contributions to the diet, especially for children and some athletes.

These are the most protein-rich of all plant foods, and they are among the few good dietary sources of the essential amino acid lysine for vegans. We recommend at least three to four servings of these foods every day for adults. Generally, one serving provides around 7 to 8 grams of protein, but many of the soyfoods, such as tempeh, veggie meats, and some types of tofu, are quite a bit higher. These foods are also important sources of minerals like iron and sometimes zinc. If your diet is based on a variety of whole grains, vegetables, and nuts, then the three recommended servings from this group are plenty. If you like to spend some discretionary calories on desserts, added fats, or more servings of fruit (which are very low in protein), shooting for four servings of legumes per day will make it easier to meet protein and lysine needs.