There are three main reasons why you might not be eating vegetables in your daily life.
First, maybe you do eat some vegetables, but you're just not eating enough of them. The CDC has done studies and, according to their data, has found that 87% of Americans don't eat enough vegetables regularly. It's simply part of American culture to focus on meat as a centerpiece to a meal.
Second, maybe you just don't like them. Maybe you grew up eating canned spinach and steamed-to-death broccoli, and you never developed a taste for them. Eating them is an unpleasant enough experience that you just choose alternatives, filling your meals with meat, fish, and bread instead.
Incidentally, if this is the case, we recommend giving them another try. A lot of vegetables admittedly taste awful when they're cooked poorly. Instead of steaming them, try roasting them with a bit of lemon and spices, for example. "Vegetables" is a really broad category, and you can always try different preparations to find something you like.
Plus, hey, sometimes vegetables just taste better now. Did you know that a group of scientists in the Netherlands have spent over a decade selectively breeding Brussels sprouts to make them taste better? It's true! If you have bad memories of the bitter, cabbage-like balls from your childhood, well, they're practically an entirely new vegetable these days.
The third reason you might be avoiding vegetables is when you're focusing on a carnivore diet. There are a lot of diets that preferentially focus on meat, like Keto, Paleo, and Primal diets, but they still work in plenty of veg. Carnivore diets, meanwhile, focus entirely on meat and exclude plant matter, as a sort of anti-vegan dietary movement.
One potential, albeit rare, fourth reason to avoid vegetables is allergies. Some people are legitimately allergic to some vegetables, like alliums, nightshades, or pollen food syndrome. This is really quite rare, though, and if you think you're allergic to vegetables, we recommend seeing an allergist to get tested and figure out what, specifically, is actually triggering your allergies.
What You're Missing Without Vegetables
If you're not eating vegetables, or you're not eating enough vegetables, you're going to be missing out on a selection of key nutrients that your body needs to survive. Some of them you can live without for a long time, while others will increase things like fatigue levels or your risk of diabetes. Others might simply induce unpleasant side effects, like diarrhea. So what might you end up missing, and how can you get it from non-veg sources? We've identified the ten most prominent ingredients you'll need to supplement.
1. Fiber
The number one element you're missing with a low- or no-vegetable diet is fiber. Fiber is something you'll notice you're missing pretty quick, but you might not draw the connection. A lack of fiber leads to either diarrhea or constipation. 
Fiber is a "prebiotics" and a binder for the material that passes through your intestines. It fuels your gut flora and allows your digestive system to function properly. Modern studies are even indicating that fiber may be better than probiotics themselves at regulating your gut biome.
Most dietary fiber typically comes from plant matter, so if you're not eating enough vegetables, you're going to want to take some kind of fiber supplement. Science recommends around 25 grams of fiber every day for women, and 38 grams daily for men.
You can get fiber supplements in various forms, including methylcellulose, psyllium, inulin, and wheat dextrin. You can also simply strive to eat more vegetables that are high in fiber, such as beans, lentils, and artichokes. If you want something sweeter, raspberries are also high.
2. Vitamin A
Vitamin A is sometimes an issue with carnivore diets, and sometimes not. It depends on what specifically you're eating. Liver, for example, is high in vitamin A on its own, so you can eat that and be fine without a supplement. If you prefer leaner meats like chicken, though, you're going to want to get your vitamin A somewhere else.
Obviously, you can pick up a vitamin A supplement anywhere you can get vitamins. If you're interested in a compound or multi-vitamin, look for something with a sufficient quantity of Retinol.
The vegetable-based option is typically beta-carotene. This compound isn't vitamin A itself, but the body breaks it down into vitamin A when you digest it. You can get this from everything from carrots to grass-fed steak.
One thing to note, though, is that you don't want to take too much vitamin A if you're a woman who is or is looking to become pregnant. High levels of vitamin A have been linked to some birth defects.
3. Vitamins B7 and B9
There are a whole bunch of different B vitamins, and they all interact with your system in different ways. They come from a variety of different sources, as well. Other than the typical Bs, there are some less common B vitamins you might pick up in your diet as well, but they aren't a primary concern.
Vitamin B7, also known as biotin, is an important vitamin for hair health and skin health. Vitamin B9, aka folate, is meanwhile a potent vitamin for regulating healthy blood.
Neither of these vitamins is rare in meat, but you have to either eat vitamin-rich meat or other protein sources, or you should top them off with a supplement. For food sources, you can get more of these vitamins from liver, eggs, and salmon. Alternatively, eat more leafy greens to get more than enough of both of them.
As far as supplements go, you can't go wrong with a B Complex multivitamin. The B Complex typically includes B1, B2, B3, B5, B6, B7, B9, and B12 in an appropriate mixture to get you your daily intake in a single capsule.
4. Vitamin C
Vitamin C is a critical vitamin that you probably know all about as a driver of the immune system. Well, it might not be quite as potent as folklore will have you suggest, but it's still critical to eat enough of the vitamin to avoid deficiency. Deficiency in vitamin C causes scurvy, which is definitely not something you want to experience. Unless, you know, you're a fan of bleeding from your gums.
Vitamin C is something you're not going to find in meat pretty much at all. Even when you find it, you won't be getting a lot of it, unless you're eating non-standard organ sources. We're talking things like lung, spleen, and thymus here. Worse, cooking the meat destroys the vitamin C, so you need to eat them raw.
Rather than that, why not eat some fruit? Vitamin C is present in citrus, tomato, and kiwi. You can also get it from peppers, broccoli, and Brussels sprouts. And, of course, you're always able to just pick up one of those tangy chewable vitamin C tablets, or a more condensed and swallowable supplement tablets.
5. Vitamin E
Vitamin E is one of the more common antioxidants you can get from your diet. It's most often used in the body when your body burns fat for energy, which is what you'll be doing if you're on a carnivore diet. A diet full of carbs, less so. A lack of vitamin E can lead to high levels of oxidative stress, tissue damage, and other issues.
Vitamin E can be found in a few meat-adjacent foods, like snails, fish eggs, and salmon, but you're going to have to eat a decent amount every day to get the vitamins you really need.
To get vitamin E from food-based sources, you're typically going to want to eat seeds and nuts, usually those that have fat or oil in them. Sunflower seeds, almonds, and pine nuts are all good choices.
You can also simply take a supplement. Vitamin E is a core component of a lot of multivitamins, and you can, of course, just get it as a stand-alone vitamin supplement as well.
6. Vitamin K
Vitamin K is a crucial vitamin your body needs for healthy bones, bone healing, and blood clotting. Without it, you'll end up with osteoporosis and bleeding issues. Most people tend to get their vitamin K from leafy greens, with smaller amounts present in a variety of other foods.
In a meat-focused diet, you can sometimes get enough vitamin K from eating enough chicken and pork regularly, though you may have to eat enough of it to reach that point. This can be tricky if you're also eating a bunch of liver and beef to get other nutrients. You can also get some vitamin K from tuna, though you'll need to eat 200+ grams to get enough per day.
Vitamin K supplements are not hard to come by, both as your typical multivitamin or as a stand-alone supplement. Since so much of your potential deficiencies are vitamins, a multivitamin might not be a bad idea. However, you may want to do a blood test or two to figure out if you're overdoing it on any particular vitamins and should do a few individual supplements instead.
7. Calcium
Calcium is a critical mineral for bone health, as well as blood pressure regulation, muscle function, hormone signaling, and nerve health. It does a lot.
The trick with calcium is that a lot of foods are fortified with additional calcium, like dairy and cereal. However, calcium alone isn't going to do you much good. Why? Without vitamin K, your body can't absorb much of that calcium. It just passes right through you. It would be like trying to fish without a hook or a net. There are plenty of fish there, but you have no way to catch them.
Calcium can also be found in boney fish like sardines, beef tripe, and a few other meat-based sources. You can even get a little bit from Himalayan salt, but you'd have to eat a LOT of salt to get a sufficient amount of calcium, and that'll hurt you more than help.
If you need more calcium in your diet, drinking some dairy is generally the easiest way. If you want a supplement, make sure you're getting enough of both vitamin K and calcium so you can absorb them both.
8. Potassium
Potassium, in your body, is used to regulate fluid balance and blood pressure. Too much potassium can lead to kidney issues, but too little of it can cause kidney stones, high blood pressure, and an irregular heartbeat. You're going to want a lot of it too; the daily recommended amount is 3,400-4,500 mg.
Potassium is naturally found in a lot of fruits and vegetables, but it's also available in some quantity in red meat. Potatoes, beans, and greens are good sources as well.
A potassium supplement will not be hard to find and, of course, a good multivitamin will include both vitamins and minerals to make the most out of your single supplement.
9. Magnesium
Magnesium is an essential mineral, which means your body cannot produce it and you have to get it from your food. It's also one of the most prevalent and most necessary minerals; it has fingers in pretty much every part of your bodily pie. It's used in metabolism, in DNA synthesis, in mood regulation, and a whole lot else besides.
Magnesium is usually found in nuts and beans, but you can also get it from mollusks, salmon, and bone broth, but only if the bone broth has been boiled for at least 12 hours to extract the magnesium from the bones.
Magnesium is easy to find as a supplement, particularly in the bioavailable magnesium citrate. Be careful not to take too much, though, because mag citrate is also used as a laxative, and it works quite well.
10. Polyphenols
While not technically a single nutrient, polyphenols are a range of antioxidants you get from plants. They help protect against heart disease, nerve damage, and a range of other problems.
In order to get polyphenols, you're going to want to either get them from plants directly or as supplements. You can pick up some curcumin, lycopene, or pterostilbene supplements fairly easily. You can also get a bunch from green tea, and green tea extracts found in some supplements.
What about oxalic and other acids??