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Vitamins are substances that your body needs to grow and develop normally. Vitamin A plays a role in your:

• Vision
• Bone growth
• Reproduction
• Cell functions
• Immune system

Vitamin A is an antioxidant. It can come from plant or animal sources. Plant sources include colorful fruits and vegetables. Animal sources include liver and whole milk. Vitamin A is also added to foods like cereals.

Vegetarians, young children, and alcoholics may need extra Vitamin A. You might also need more if you have certain conditions, such as liver diseases, cystic fibrosis, and Crohn's disease. Check with your health care provider to see if you need to take vitamin A supplements.

NIH: National Institutes of Health Office of Dietary Supplements

Antioxidants are man-made or natural substances that may prevent or delay some types of cell damage. Antioxidants are found in many foods, including fruits and vegetables. They are also available as dietary supplements. Examples of antioxidants include:

• Beta-carotene
• Lutein
• Lycopene
• Selenium
• Vitamin A
• Vitamin C
• Vitamin E

Vegetables and fruits are rich sources of antioxidants. There is good evidence that eating a diet with lots of vegetables and fruits is healthy and lowers risks of certain diseases. But it isn't clear whether this is because of the antioxidants, something else in the foods, or other factors.

High-dose supplements of antioxidants may be linked to health risks in some cases. For example, high doses of beta-carotene may increase the risk of lung cancer in smokers. High doses of vitamin E may increase risks of prostate cancer and one type of stroke. Antioxidant supplements may also interact with some medicines. To minimize risk, tell your health care providers about any antioxidants you use.

NIH: National Center for Complementary and Integrative Health

Vitamins are substances that your body needs to grow and develop normally. There are 13 vitamins your body needs. They are:

• Vitamin A
• B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate)
• Vitamin C
• Vitamin D
• Vitamin E
• Vitamin K

You can usually get all your vitamins from the foods you eat. Your body can also make vitamins D and K. People who eat a vegetarian diet may need to take a vitamin B12 supplement.

Each vitamin has specific jobs. If you have low levels of certain vitamins, you may get health problems. For example, if you don't get enough vitamin C, you could become anemic. Some vitamins may help prevent medical problems. Vitamin A prevents night blindness.

The best way to get enough vitamins is to eat a balanced diet with a variety of foods. In some cases, you may need to take vitamin supplements. It's a good idea to ask your health care provider first. High doses of some vitamins can cause problems.

Nutrition is about eating a healthy and balanced diet so your body gets the nutrients that it needs. Nutrients are substances in foods that our bodies need so they can function and grow. They include carbohydrates, fats, proteins, vitamins, minerals, and water.

When you're pregnant, nutrition is more important than ever. You need more of many important nutrients than you did before pregnancy. Making healthy food choices every day will help you give your baby what they need to develop. It will also help make sure that you and your baby gain a healthy amount of weight.

You need more folic acid, iron, calcium, and vitamin D than you did before pregnancy:

• Folic acid is a B vitamin that may help prevent neural tube defects.
  • Before pregnancy, you need 400 mcg (micrograms) per day.
  • During pregnancy and when breastfeeding, you need 600 mcg per day from foods and/or vitamins. It is hard to get this amount from foods alone, so you will most likely need to take a supplement that contains folic acid.
• Iron is important for your baby's growth and brain development. During pregnancy, the amount of blood in your body increases, so you need more iron for yourself and your growing baby. You should get 27 mg (milligrams) of iron a day.
• Calcium during pregnancy can reduce your risk of preeclampsia. It's a serious medical condition that causes a sudden increase in your blood pressure. Calcium also builds up your baby's bones and teeth.
• Pregnant adults should get 1,000 mg (milligrams) of calcium a day
• Pregnant teenagers (ages 14-18) need 1,300 mg of calcium a day
• Vitamin D helps the calcium to build up the baby's bones and teeth. All women, pregnant or not, should be getting 600 IU (international units) of vitamin D per day.

Keep in mind that taking too much of a supplement can be harmful. For example, very high levels of vitamin A can cause birth defects. Only take vitamins and mineral supplements that your health care provider recommends.

You also need more protein when you are pregnant. Healthy sources of protein include beans, peas, eggs, lean meats, seafood, and unsalted nuts and seeds.

Getting enough fluids is another special nutritional concern during pregnancy. When you are pregnant, your body needs even more water to stay hydrated and support the life inside you. So it's important to drink enough fluids every day.

How much weight you should gain depends on your health and how much you weighed before pregnancy:

• If you were at a normal weight before pregnancy, you should gain about 25 to 35 pounds
• If you were underweight before pregnancy, you should gain more
• If you were overweight or had obesity before you became pregnant, you should gain less

Check with your provider to find out how much weight gain during pregnancy is healthy for you. You should gain the weight gradually during your pregnancy, with most of the weight gained in the last trimester.

How many calories you need depends on your weight gain goals. Your provider can tell you what your goal should be, based on things like your weight before pregnancy, your age, and how fast you gain weight. The general recommendations are:

• In the first trimester of pregnancy, you probably do not need extra calories
• In the second trimester, you usually need about 340 extra calories
• In the last trimester, you may need around 450 extra calories per day
• During the final weeks of pregnancy, you may not need extra calories

Keep in mind that not all calories are equal. You should eat healthy foods that are packed with nutrients - not "empty calories" such as those found in soft drinks, candies, and desserts.

During pregnancy, you should avoid:

• Alcohol. There is no known amount of alcohol that is safe for a woman to drink during pregnancy.
• Fish that may have high levels of mercury. Limit white (albacore) tuna to 6 ounces per week. Do not eat tilefish, shark, swordfish, marlin, orange roughy, or king mackerel.
• Foods that are more likely to contain germs that could cause foodborne illness, including
  • Refrigerated smoked seafood like whitefish, salmon, and mackerel
  • Undercooked meat, poultry, eggs, and seafood
  • Refrigerated meat spreads
  • Store-made salads, such as chicken, egg, or tuna salad
  • Unpasteurized or raw milk
  • Unpasteurized juices or cider
  • Unpasteurized soft cheeses, such as unpasteurized feta, Brie, queso blanco, queso fresco, and blue cheeses
  • Raw sprouts of any kind (including alfalfa, clover, radish, and mung bean)
  • Raw cookie dough
  • Unwashed fruits and vegetables
• Too much caffeine. Drinking high amounts of caffeine may be harmful for your baby. For most people, it's best to limit caffeine to less than 200 mg per day during pregnancy. But first check with your provider about whether you should have caffeine at all.

Carbohydrates, or carbs, are sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks.

Your body breaks down carbohydrates into glucose. Glucose, or blood sugar, is the main source of energy for your body's cells, tissues, and organs. Glucose can be used immediately or stored in the liver and muscles for later use.

There are three main types of carbohydrates:

• Sugars. They are also called simple carbohydrates because they are in the most basic form. They can be added to foods, such as the sugar in candy, desserts, processed foods, and regular soda. They also include the kinds of sugar that are found naturally in fruits, vegetables, and milk.
• Starches. They are complex carbohydrates, which are made of lots of simple sugars strung together. Your body needs to break starches down into sugars to use them for energy. Starches include bread, cereal, and pasta. They also include certain vegetables, like potatoes, peas, and corn.
• Fiber. It is also a complex carbohydrate. Your body cannot break down most fibers, so eating foods with fiber can help you feel full and make you less likely to overeat. Diets high in fiber have other health benefits. They may help prevent stomach or intestinal problems, such as constipation. They may also help lower cholesterol and blood sugar. Fiber is found in many foods that come from plants, including fruits, vegetables, nuts, seeds, beans, and whole grains.

Common foods with carbohydrates include:

• Grains, such as bread, noodles, pasta, crackers, cereals, and rice
• Fruits, such as apples, bananas, berries, mangoes, melons, and oranges
• Dairy products, such as milk and yogurt
• Legumes, including dried beans, lentils, and peas
• Snack foods and sweets, such as cakes, cookies, candy, and other desserts
• Juices, regular sodas, fruit drinks, sports drinks, and energy drinks that contain sugar
• Starchy vegetables, such as potatoes, corn, and peas

Some foods don't have a lot of carbohydrates, such as meat, fish, poultry, some types of cheese, nuts, and oils.

You do need to eat some carbohydrates to give your body energy. But it's important to eat the right kinds of carbohydrates for your health:

• When eating grains, choose mostly whole grains and not refined grains:
  • Whole grains are foods like whole-wheat bread, brown rice, whole cornmeal, and oatmeal. They offer lots of nutrients that your body needs, like vitamins, minerals, and fiber. To figure out whether a product has a lot of whole grain, check the ingredients list on the package and see if a whole grain is one of the first few items listed.
  • Refined grains are foods that have had some parts of the grains removed. This also removes some of the nutrients that are good for your health.
• Eat foods with lots of fiber. The Nutrition Facts labels on the back of food packages tells you how much fiber a product has.
• Try to avoid foods that have a lot of added sugar. These foods can have many calories but not much nutrition. Eating too much added sugar raises your blood sugar and can make you gain weight. You can tell if a food or drink has added sugars by looking at the Nutrition Facts label on the back of the food package. It tells you how much total sugar and added sugar is in that food or drink.

There is no one-size-fits-all amount of carbohydrates that people should eat. This amount can vary, depending on factors such as your age, sex, health, and whether or not you are trying to lose or gain weight. On average, people should get 45 to 65% of their calories from carbohydrates every day. On the Nutrition Facts labels, the Daily Value for total carbohydrates is 275 g per day. This is based on a 2,000-calorie daily diet. Your Daily Value may be higher or lower depending on your calorie needs and health.

Some people go on a low-carb diet to try to lose weight. This usually means eating between 25 g and 150 g of carbs each day. This kind of diet can be safe, but you should talk to your health care provider before starting it. One problem with low-carb diets is that they can limit the amount of fiber you get each day. They can also be hard to stay on for the long term.

Celiac disease is a chronic (long-term) digestive and immune disorder that damages your small intestine. The damage may prevent your body from absorbing vitamins, minerals, and other nutrients from the food you eat. This can lead to malnutrition and other serious health problems

Celiac disease is triggered by eating foods that contain gluten. Gluten is a protein found in wheat, barley, rye, and other grains. It may also be in other products like vitamins and supplements, hair and skin products, toothpastes, and lip balm.

Celiac disease is different from gluten sensitivity. Both involve problems with gluten and can cause some of the same symptoms, such as abdominal (belly) pain and fatigue. But gluten sensitivity does not damage the small intestine like celiac disease does.

Wheat allergy, a type of food allergy, is also different. With both celiac disease and wheat allergy, your immune system is reacting to wheat. But with wheat allergy, you can have some different symptoms, such as itchy eyes or trouble breathing. And a wheat allergy will not cause long-term damage to the small intestine.

The exact cause of celiac disease is not known. Research suggests that celiac disease only happens in people who have certain genes and eat food that contains gluten. Researchers are studying other factors that may play a role in causing the disease.

Celiac disease is more common if you:

• Have a family member who has the disease
• Have Down syndrome, Turner syndrome, or Williams syndrome
• Are White
• Are female

The symptoms of celiac disease can be different from person to person. Sometimes the symptoms may come and go. Some people may not notice any symptoms.

Some of the possible symptoms affect your digestive system. Digestive symptoms are more common in children than in adults. The digestive symptoms include:

• Bloating (feeling fullness or swelling in your belly)
• Chronic (long-term) diarrhea or greasy, bulky, unusually bad-smelling stool (poop)
• Constipation
• Gas
• Lactose intolerance because of damage to the small intestine
• Nausea and vomiting
• Pain in the abdomen (belly)
• Weight loss in adults, or not enough weight gain in children

Some people with celiac disease have symptoms that affect other parts of the body, such as:

• Fatigue
• Depression and anxiety
• Irritability (in children)
• Dermatitis herpetiformis, an itchy rash with blisters (mainly in adults)
• Bone or joint pain
• Symptoms involving the mouth, such as canker sores or dry mouth

Over time, celiac disease can cause other health problems, especially if it is not treated. These problems can include:

• Malnutrition
• Anemia, especially iron-deficiency anemia
• Bone loss
• Nervous system problems such as headaches, balance problems, or peripheral neuropathy
• Reproductive problems, such as missed menstrual periods and miscarriages in women and infertility in men and women

If you have symptoms of celiac disease, your health care provider will look for signs that you might have celiac disease. To do this, your provider will get your medical and family history and do a physical exam.

If your provider thinks that you could have celiac disease, you will have some tests. Providers most often use blood tests and biopsies of the small intestine to diagnose celiac disease. The biopsy would be done during an upper gastrointestinal (GI) endoscopy. For this procedure, your provider uses an endoscope (a flexible tube with a camera) to see the lining of your esophagus, stomach, and small intestine. It also allows your provider to take a sample of tissue for a biopsy.

The treatment for celiac disease is following a gluten-free diet for the rest of your life. Sticking with a gluten-free diet will treat or prevent many of the symptoms and other health problems caused by celiac disease. In most cases, it can also heal damage in the small intestine and prevent more damage.

Your provider may refer you to a registered dietician (a nutrition expert) who can help you learn how to eat a healthy diet without gluten. You will also need to avoid all hidden sources of gluten, such as certain supplements, cosmetics, toothpaste, etc. Reading product labels can sometimes help you avoid gluten. If a label doesn't tell you what is in a product, check with the company that makes the product for an ingredients list. Don't just assume that a product is gluten-free if it doesn't mention it.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Crohn's disease is a chronic (long-lasting) disease that causes inflammation in your digestive tract. It can affect any part of your digestive tract, which runs from your mouth to your anus. But it usually affects your small intestine and the beginning of your large intestine.

Crohn's disease is an inflammatory bowel disease (IBD). Ulcerative colitis and microscopic colitis are other common types of IBD.

The cause of Crohn's disease is unknown. Researchers think that an autoimmune reaction may be one cause. An autoimmune reaction happens when your immune system attacks healthy cells in your body. Genetics may also play a role, since Crohn's disease can run in families.

Stress and eating certain foods don't cause the disease, but they can make your symptoms worse.

There are certain factors that may raise your risk of Crohn's disease:

• Family history of the disease. Having a parent, child, or sibling with the disease puts you at higher risk.
• Smoking. This may double your risk of developing Crohn's disease.
• Certain medicines, such as antibiotics, birth-control pills, and nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen. These may slightly increase your chance of developing Crohn's.
• A high-fat diet. This may also slightly increase your risk of Crohn's.

The symptoms of Crohn's disease can vary, depending where and how severe your inflammation is. The most common symptoms include:

• Diarrhea
• Cramping and pain in your abdomen
• Weight loss

Some other possible symptoms are:

• Anemia, a condition in which you have fewer red blood cells than normal
• Eye redness or pain
• Fatigue
• Fever
• Joint pain or soreness
• Nausea or loss of appetite
• Skin changes that involve red, tender bumps under the skin

Stress and eating certain foods such as carbonated (fizzy) drinks and high-fiber foods may make some people's symptoms worse.

Crohn's disease can cause other problems, including:

• Intestinal obstruction, a blockage in the intestine
• Fistulas, abnormal connections between two parts inside of the body
• Abscesses, pus-filled pockets of infection
• Anal fissures, small tears in your anus that may cause itching, pain, or bleeding
• Ulcers, open sores in your mouth, intestines, anus, or perineum
• Malnutrition, when your body does not get the right amount of vitamins, minerals, and nutrients it needs
• Inflammation in other areas of your body, such as your joints, eyes, and skin

Your health care provider may use many tools to make a diagnosis:

• A medical history, which includes asking about your symptoms
• A family history
• A physical exam, including:
  • Checking for bloating in your abdomen.
  • Listening to sounds within your abdomen using a stethoscope.
  • Tapping on your abdomen to check for tenderness and pain and to see if your liver or spleen is abnormal or enlarged.
• Various tests, including:
  • Blood and stool tests.
  • A colonoscopy.
  • An upper GI endoscopy, a procedure in which your provider uses a scope to look inside your mouth, esophagus, stomach, and small intestine.
  • Diagnostic imaging tests, such as a CT scan or an upper GI series. An upper GI series uses a special liquid called barium and x-rays. Drinking the barium will make your upper GI tract more visible on an x-ray.

There is no cure for Crohn's disease, but treatments can decrease inflammation in your intestines, relieve symptoms, and prevent complications. Treatments include medicines, bowel rest, and surgery. No single treatment works for everyone. You and your provider can work together to figure out which treatment is best for you:

• Medicines for Crohn's include various medicines that decrease the inflammation. Many of these medicines do this by reducing the activity of your immune system. Certain medicines can also help with symptoms or complications, such as nonsteroidal anti-inflammatory drugs and anti-diarrheal medicines. If your Crohn's causes an infection, you may need antibiotics.
• Bowel rest involves drinking only certain liquids or not eating or drinking anything. This allows your intestines to rest. You may need to do this if your Crohn's disease symptoms are severe. You get your nutrients through drinking a liquid, a feeding tube, or an intravenous (IV) tube. You may need to do bowel rest in the hospital, or you may be able to do it at home. It will last for a few days or up to several weeks.
• Surgery can treat complications and reduce symptoms when other treatments are not helping enough. The surgery will involve removing a damaged part of your digestive tract to treat:
  • Fistulas
  • Bleeding that is life threatening
  • Intestinal obstructions
  • Side effects from medicines when they threaten your health
  • Symptoms when medicines do not improve your condition

Changing your diet can help reduce symptoms. Your provider may recommend that you make changes to your diet, such as:

• Avoiding carbonated drinks
• Avoiding popcorn, vegetable skins, nuts, and other high-fiber foods
• Drinking more liquids
• Eating smaller meals more often
• Keeping a food diary to help identify foods that cause problems

In some cases, your provider may ask you to go on a special diet, such as a diet that is:

• High calorie
• Lactose free
• Low fat
• Low fiber
• Low salt

If you are not absorbing enough nutrients, you may need to take nutritional supplements and vitamins.

National Institute of Diabetes and Digestive and Kidney Diseases

Dietary supplements are vitamins, minerals, herbs, and many other products. They can come as pills, capsules, powders, drinks, and energy bars. Supplements do not have to go through the testing that drugs do.

Some supplements can play an important role in health. For example, calcium and vitamin D are important for keeping bones strong. Pregnant women can take the vitamin folic acid to prevent certain birth defects in their babies.

To take a supplement as safely as possible:

• Tell your health care provider about any dietary supplements you use
• Do not take a bigger dose than the label recommends
• Check with your health care provider about the supplements you take if you are going to have any type of surgery
• Read trustworthy information about the supplement

NIH: National Institutes of Health Office of Dietary Supplements

Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. Fatty liver disease is a condition in which fat builds up in your liver. There are two main types:

• Nonalcoholic fatty liver disease (NAFLD)
• Alcoholic fatty liver disease, also called alcoholic steatohepatitis

NAFLD is a type of fatty liver disease that is not related to heavy alcohol use. There are two kinds:

• Simple fatty liver, in which you have fat in your liver but little or no inflammation or liver cell damage. Simple fatty liver typically does not get bad enough to cause liver damage or complications.
• Nonalcoholic steatohepatitis (NASH), in which you have inflammation and liver cell damage, as well as fat in your liver. Inflammation and liver cell damage can cause fibrosis, or scarring, of the liver. NASH may lead to cirrhosis or liver cancer.

Alcoholic fatty liver disease is due to heavy alcohol use. Your liver breaks down most of the alcohol you drink, so it can be removed from your body. But the process of breaking it down can generate harmful substances. These substances can damage liver cells, promote inflammation, and weaken your body's natural defenses. The more alcohol that you drink, the more you damage your liver. Alcoholic fatty liver disease is the earliest stage of alcohol-related liver disease. The next stages are alcoholic hepatitis and cirrhosis.

The cause of nonalcoholic fatty liver disease (NAFLD) is unknown. Researchers do know that it is more common in people who:

• Have type 2 diabetes and prediabetes
• Have obesity
• Are middle aged or older (although children can also get it)
• Are Hispanic, followed by non-Hispanic whites. It is less common in African Americans.
• Have high levels of fats in the blood, such as cholesterol and triglycerides
• Have high blood pressure
• Take certain drugs, such as corticosteroids and some cancer drugs
• Have certain metabolic disorders, including metabolic syndrome
• Have rapid weight loss
• Have certain infections, such as hepatitis C
• Have been exposed to some toxins

NAFLD affects about 25% of people in the world. As the rates of obesity, type 2 diabetes, and high cholesterol are rising in the United States, so is the rate of NAFLD. NAFLD is the most common chronic liver disorder in the United States.

Alcoholic fatty liver disease only happens in people who are heavy drinkers, especially those who have been drinking for a long period of time. The risk is higher for heavy drinkers who are women, have obesity, or have certain genetic mutations.

Both NAFLD and alcoholic fatty liver disease are usually silent diseases with few or no symptoms. If you do have symptoms, you may feel tired or have discomfort in the upper right side of your abdomen.

Because there are often no symptoms, it is not easy to find fatty liver disease. Your doctor may suspect that you have it if you get abnormal results on liver tests that you had for other reasons. To make a diagnosis, your doctor will use:

• Your medical history
• A physical exam
• Various tests, including blood and imaging tests, and sometimes a biopsy

As part of the medical history, your doctor will ask about your alcohol use, to find out whether fat in your liver is a sign of alcoholic fatty liver disease or nonalcoholic fatty liver (NAFLD). He or she will also ask which medicines you take, to try to determine whether a medicine is causing your NAFLD.

During the physical exam, your doctor will examine your body and check your weight and height. Your doctor will look for signs of fatty liver disease, such as:

• An enlarged liver
• Signs of cirrhosis, such as jaundice, a condition that causes your skin and whites of your eyes to turn yellow

You will likely have blood tests, including liver function tests and blood count tests. In some cases you may also have imaging tests, like those that check for fat in the liver and the stiffness of your liver. Liver stiffness can mean fibrosis, which is scarring of the liver. In some cases you may also need a liver biopsy to confirm the diagnosis, and to check how bad the liver damage is.

Doctors recommend weight loss for nonalcoholic fatty liver. Weight loss can reduce fat in the liver, inflammation, and fibrosis. If your doctor thinks that a certain medicine is the cause of your NAFLD, you should stop taking that medicine. But check with your doctor before stopping the medicine. You may need to get off the medicine gradually, and you might need to switch to another medicine instead.

There are no medicines that have been approved to treat NAFLD. Studies are investigating whether a certain diabetes medicine or Vitamin E can help, but more studies are needed.

The most important part of treating alcohol-related fatty liver disease is to stop drinking alcohol. If you need help doing that, you may want to see a therapist or participate in an alcohol recovery program. There are also medicines that can help, either by reducing your cravings or making you feel sick if you drink alcohol.

Both alcoholic fatty liver disease and one type of nonalcoholic fatty liver disease (nonalcoholic steatohepatitis) can lead to cirrhosis. Doctors can treat the health problems caused by cirrhosis with medicines, operations, and other medical procedures. If the cirrhosis leads to liver failure, you may need a liver transplant.

If you have any of the types of fatty liver disease, there are some lifestyle changes that can help:

• Eat a healthy diet, limiting salt and sugar, plus eating lots of fruits, vegetables, and whole grains
• Get vaccinations for hepatitis A and B, the flu and pneumococcal disease. If you get hepatitis A or B along with fatty liver, it is more likely to lead to liver failure. People with chronic liver disease are more likely to get infections, so the other two vaccinations are also important.
• Get regular exercise, which can help you lose weight and reduce fat in the liver
• Talk with your doctor before using dietary supplements, such as vitamins, or any complementary or alternative medicines or medical practices. Some herbal remedies can damage your liver.

Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth defects of her baby's brain or spine.

Foods with folic acid in them include:

• Leafy green vegetables
• Fruits
• Dried beans, peas, and nuts
• Enriched breads, cereals and other grain products

If you don't get enough folic acid from the foods you eat, you can also take it as a dietary supplement.

NIH: National Institutes of Health Office of Dietary Supplements