It would be best to eat a diverse diet. If you're not going to do that, a multi-vitamin and mineral supplement would be best. Keep in mind that this will not provide the protein, carbs or other fuels you need.
You can use a cooling rack or a bed of vegetables as a substitute for a roasting rack.
Fruit juices are good potassium supplements. You can have soup of various leafy vegetables as potassium supplements. As such potassium is integral part of all cells. So any cells you are eating will provide you with potassium supplements. In the last you can have diluted market preparations available as potassium supplements.
Mineral supplements are known as a way of plugging a gap in your food diet. They are not meant to be a substitute, but rather an aid if you happen to be allergic or dislike a particular good group.
Even the best supplement is no substitute for ... People who often eat processed and to a basic healthy diet and lifestyle, An herbal supplement or vitamin.
Dietary supplements are anything you eat besides food so they are vitamins, herbs, amino acids or parts of these substances. They add to, or supplement, the diet and are not a substitute for food. The Office of Dietary Supplements has an A to Z list of supplements. http://ods.od.nih.gov/factsheets/list-all
Eat a variety of foods; especially fruits and vegetables. There are vegetarian vitamin supplements.
A good substitute for rutabaga in recipes is turnip. Both vegetables have a similar flavor profile and can be used interchangeably in many dishes.
You can use spiralized vegetables like zucchini or sweet potato, or even spaghetti squash as a substitute for rice noodles in a recipe.
Artichoke can be used as a substitute for burdock, since the two are closely related. You could also substitute other root vegetables, such as turnips, parsnips, or radishes.
Black beans ARE a vegetable . . . yes, it is a serving.
Bok choy is a member of the Brassica rapa family of vegetables, along with turnip greens and Napa cabbage, so you could possibly substitute either of those.
A suitable substitute for bell pepper in this recipe could be a combination of other colorful vegetables like zucchini, carrots, or mushrooms to maintain flavor and texture.