ergocalciferol

Vitamins are substances that your body needs to grow and develop normally. Vitamin D helps your body absorb calcium. Calcium is one of the main building blocks of bone. A lack of vitamin D can lead to bone diseases such as osteoporosis or rickets. Vitamin D also has a role in your nerve, muscle, and immune systems.

You can get vitamin D in three ways: through your skin, from your diet, and from supplements. Your body forms vitamin D naturally after exposure to sunlight. However, too much sun exposure can lead to skin aging and skin cancer. So many people try to get their vitamin D from other sources.

Vitamin D-rich foods include egg yolks, saltwater fish, and liver. Some other foods, like milk and cereal, often have added vitamin D.

You can also take vitamin D supplements. Check with your health care provider to see how much you should take. People who might need extra vitamin D include:

• Older adults
• Breastfed infants
• People with dark skin
• People with certain conditions, such as liver diseases, cystic fibrosis and Crohn's disease
• People who have obesity or have had gastric bypass surgery

NIH: National Institutes of Health Office of Dietary Supplements

Vitamin D deficiency means that your body is not getting enough vitamin D to stay healthy.

Vitamin D helps your body absorb calcium. Calcium is one of the main building blocks of bone. Vitamin D also has a role in your nervous, muscle, and immune systems.

You can get vitamin D in three ways: through your skin, from your diet, and from supplements. Your body forms vitamin D naturally after exposure to sunlight. But too much sun exposure can lead to skin aging and skin cancer, so many people try to get their vitamin D from other sources.

The amount of vitamin D you need each day depends on your age. The recommended amounts, in international units (IU), are:

• Birth to 12 months: 400 IU
• Children 1-13 years: 600 IU
• Teens 14-18 years: 600 IU
• Adults 19-70 years: 600 IU
• Adults 71 years and older: 800 IU
• Pregnant and breastfeeding women: 600 IU

People at high risk of vitamin D deficiency may need more. Check with your health care provider about how much you need.

You can become deficient in vitamin D for different reasons:

• You don't get enough vitamin D in your diet
• You don't absorb enough vitamin D from food (a malabsorption problem)
• You don't get enough exposure to sunlight
• Your liver or kidneys cannot convert vitamin D to its active form in the body
• You take medicines that interfere with your body's ability to convert or absorb vitamin D

Some people are at higher risk of vitamin D deficiency:

• Breastfed infants, because human milk is a poor source of vitamin D. If you are breastfeeding, give your infant a supplement of 400 IU of vitamin D every day.
• Older adults, because your skin doesn't make vitamin D when exposed to sunlight as efficiently as when you were young, and your kidneys are less able to convert vitamin D to its active form.
• People with dark skin, which has less ability to produce vitamin D from the sun.
• People with conditions that make it difficult to absorb nutrients from food, such as Crohn's disease, ulcerative colitis, and celiac disease.
• People who have obesity, because their body fat binds to some vitamin D and prevents it from getting into the blood.
• People who have had gastric bypass surgery, a type of weight loss surgery which creates a bypass of part of the small intestine. Since vitamin D is absorbed there, bypassing part of it makes it harder to absorb enough vitamin D.
• People with chronic kidney or liver disease, which can affect your ability to change vitamin D into a form your body can use.
• People who take medicines that affect vitamin D levels, including certain cholesterol, anti-seizure, steroid, and weight-loss medicines.

Talk with your provider if you are at risk for vitamin D deficiency. There is a blood test that can measure how much vitamin D is in your body.

Vitamin D deficiency can lead to a loss of bone density, which can contribute to osteoporosis and fractures (broken bones).

Severe vitamin D deficiency can also lead to other diseases:

• In children, it can cause rickets. Rickets is a rare disease that causes the bones to become soft and bend. African American infants and children are at higher risk of getting rickets.
• In adults, severe vitamin D deficiency leads to osteomalacia. Osteomalacia causes weak bones, bone pain, and muscle weakness.

There are a few foods that naturally have some vitamin D:

• Fatty fish such as salmon, tuna, and mackerel
• Beef liver
• Cheese
• Mushrooms
• Egg yolks

You can also get vitamin D from fortified foods. You can check the food labels to find out whether a food has vitamin D. Foods that often have added vitamin D include:

• Milk
• Breakfast cereals
• Orange juice
• Other dairy products, such as yogurt
• Soy drinks

Vitamin D is in many multivitamins. There are also vitamin D supplements, both in pills and in a liquid for babies.

If you have vitamin D deficiency, the treatment is with supplements. Check with your provider about how much you need to take, how often you need to take it, and how long you need to take it.

Getting too much vitamin D (known as vitamin D toxicity) can be harmful. Signs of toxicity include nausea and vomiting, poor appetite, constipation, weakness, and weight loss.

Very high levels of vitamin D can damage the kidneys. It also raises the level of calcium in your blood. High levels of blood calcium (hypercalcemia) can cause confusion, kidney failure, and irregular heartbeat (arrhythmia).

Most cases of vitamin D toxicity happen when someone overuses vitamin D supplements. You cannot get too much vitamin D from sun exposure because the skin limits the amount of vitamin D it makes.

Rickets causes soft, weak bones in children. It usually occurs when they do not get enough vitamin D, which helps growing bones absorb the minerals calcium and phosphorous. It can also happen when calcium or phosphorus levels are too low.

Your child might not get enough vitamin D if he or she:

• Has dark skin
• Spends too little time outside
• Has on sunscreen all the time when out of doors
• Doesn't eat foods containing vitamin D because of lactose intolerance or a strict vegetarian diet
• Is breastfed without receiving vitamin D supplements
• Can't make or use vitamin D because of a medical disorder such as celiac disease

In addition to dietary rickets, children can get an inherited form of the disease. Symptoms include bone pain or tenderness, impaired growth, and deformities of the bones and teeth. Your child's doctor uses lab and imaging tests to make the diagnosis. Treatment is replacing the calcium, phosphorus, or vitamin D that are lacking in the diet. Rickets is rare in the United States.

You have more calcium in your body than any other mineral. Calcium has many important jobs. The body stores more than 99% of its calcium in the bones and teeth to help make and keep them strong. The rest is throughout the body in blood, muscle and the fluid between cells. Your body needs calcium to help muscles and blood vessels contract and expand, to secrete hormones and enzymes and to send messages through the nervous system.

It is important to get plenty of calcium in the foods you eat. Foods rich in calcium include:

• Dairy products such as milk, cheese, and yogurt
• Leafy, green vegetables
• Fish with soft bones that you eat, such as canned sardines and salmon
• Calcium-enriched foods such as breakfast cereals, fruit juices, soy and rice drinks, and tofu. Check the product labels.

The exact amount of calcium you need depends on your age and other factors. Growing children and teenagers need more calcium than young adults. Older women need plenty of calcium to prevent osteoporosis. People who do not eat enough high-calcium foods should take a calcium supplement.

NIH: National Institutes of Health Office of Dietary Supplements

Osteoporosis is a disease that thins and weakens the bones. Your bones become fragile and fracture (break) easily, especially the bones in the hip, spine, and wrist. In the United States, millions of people either already have osteoporosis or are at high risk due to low bone mass.

Anyone can develop osteoporosis, but it is more common in older women. Risk factors include:

• Getting older
• Being small and thin
• Having a family history of osteoporosis
• Taking certain medicines
• Being a white or Asian woman
• Having low bone density

Osteoporosis is a silent disease. You might not know you have it until you break a bone. A bone mineral density test is the best way to check your bone health.

To keep bones strong, eat a diet rich in calcium and vitamin D, exercise, and do not smoke. If needed, medicines can also help. It is also important to try to avoid falling down. Falls are the number one cause of fractures in older adults.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

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.

Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms new cells as you need them, replacing old cells that die. Sometimes this process goes wrong. New cells grow even when you don't need them, and old cells don't die when they should. These extra cells can form a mass called a tumor. Tumors can be benign or malignant. Benign tumors aren't cancer while malignant ones are. Cells from malignant tumors can invade nearby tissues. They can also break away and spread to other parts of the body.

Cancer is not just one disease but many diseases. There are more than 100 different types of cancer. Most cancers are named for where they start. For example, lung cancer starts in the lung, and breast cancer starts in the breast. The spread of cancer from one part of the body to another is called metastasis. Symptoms and treatment depend on the cancer type and how advanced it is. Most treatment plans may include surgery, radiation and/or chemotherapy. Some may involve hormone therapy, immunotherapy or other types of biologic therapy, or stem cell transplantation.

NIH: National Cancer Institute

Multiple sclerosis (MS) is a nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of MS. They can include:

• Visual disturbances
• Muscle weakness
• Trouble with coordination and balance
• Sensations such as numbness, prickling, or "pins and needles"
• Thinking and memory problems

No one knows what causes MS. It may be an autoimmune disease, which happens when your immune system attacks healthy cells in your body by mistake. Multiple sclerosis affects women more than men. It often begins between the ages of 20 and 40. Usually, the disease is mild, but some people lose the ability to write, speak, or walk.

There is no specific test for MS. Doctors use a medical history, physical exam, neurological exam, MRI, and other tests to diagnose it. There is no cure for MS, but medicines may slow it down and help control symptoms. Physical and occupational therapy may also help.

NIH: National Institute of Neurological Disorders and Stroke

Primary ovarian insufficiency (POI), also known as premature ovarian failure, happens when a woman's ovaries stop working normally before she is 40.

Many women naturally experience reduced fertility when they are about 40 years old. They may start getting irregular menstrual periods as they transition to menopause. For women with POI, irregular periods and reduced fertility start before the age of 40. Sometimes it can start as early as the teenage years.

POI is different from premature menopause. With premature menopause, your periods stop before age 40. You can no longer get pregnant. The cause can be natural or it can be a disease, surgery, chemotherapy, or radiation. With POI, some women still have occasional periods. They may even get pregnant. In most cases of POI, the cause is unknown.

In about 90% of cases, the exact cause of POI is unknown.

Research shows that POI is related to problems with the follicles. Follicles are small sacs in your ovaries. Your eggs grow and mature inside them. One type of follicle problem is that you run out of working follicles earlier than normal. Another is that the follicles are not working properly. In most cases, the cause of the follicle problem is unknown. But sometimes the cause may be:

• Genetic disorders such as Fragile X syndrome and Turner syndrome
• A low number of follicles
• Autoimmune diseases, including thyroiditis and Addison disease
• Chemotherapy or radiation therapy
• Metabolic disorders
• Toxins, such as cigarette smoke, chemicals, and pesticides

Certain factors can raise a woman's risk of POI:

• Family history. Women who have a mother or sister with POI are more likely to have it.
• Genes. Some changes to genes and genetic conditions put women at higher risk for POI. For example, women Fragile X syndrome or Turner syndrome are at higher risk.
• Certain diseases, such as autoimmune diseases and viral infections
• Cancer treatments, such as chemotherapy and radiation therapy
• Age. Younger women can get POI, but it becomes more common between the ages of 35-40.

The first sign of POI is usually irregular or missed periods. Later symptoms may be similar to those of natural menopause:

• Hot flashes
• Night sweats
• Irritability
• Poor concentration
• Decreased sex drive
• Pain during sex
• Vaginal dryness

For many women with POI, trouble getting pregnant or infertility is the reason they go to their health care provider.

Since POI causes you to have lower levels of certain hormones, you are at greater risk for other health conditions, including:

• Anxiety and depression. Hormonal changes caused by POI can contribute to anxiety or lead to depression.
• Dry eye syndrome and eye surface disease. Some women with POI have one of these eye conditions. Both can cause discomfort and may lead to blurred vision. If not treated, these conditions can cause permanent eye damage.
• Heart disease. Lower levels of estrogen can affect the muscles lining the arteries and can increase the buildup of cholesterol in the arteries. These factors increase your risk of atherosclerosis (hardening of the arteries).
• Infertility.
• Low thyroid function. This problem also is called hypothyroidism. The thyroid is a gland that makes hormones that control your body's metabolism and energy level. Low levels thyroid hormones can affect your metabolism and can cause very low energy, mental sluggishness, and other symptoms.
• Osteoporosis. The hormone estrogen helps keep bones strong. Without enough estrogen, women with POI often develop osteoporosis. It is a bone disease that causes weak, brittle bones that are more likely to break.

To diagnose POI, your health care provider may do:

• A medical history, including asking whether you have relatives with POI
• A pregnancy test, to make sure that you are not pregnant
• A physical exam, to look for signs of other disorders which could be causing your symptoms
• Blood tests, to check for certain hormone levels. You may also have a blood test to do a chromosome analysis. A chromosome is the part of a cell that contains genetic information.
• A pelvic ultrasound, to see whether or not the ovaries are enlarged or have multiple follicles

Currently, there is no proven treatment to restore normal function to a woman's ovaries. But there are treatments for some of the symptoms of POI. There are also ways to lower your health risks and treat the conditions that POI can cause:

• Hormone replacement therapy (HRT).HRT is the most common treatment. It gives your body the estrogen and other hormones that your ovaries are not making. HRT improves sexual health and decreases the risks for heart disease and osteoporosis. You usually take it until about age 50; that's about the age when menopause usually begins.
• Calcium and vitamin D supplements. Because women with POI are at higher risk for osteoporosis, you should take calcium and vitamin D every day.
• In vitro fertilization (IVF). If you have POI and you wish to become pregnant, you may consider trying IVF.
• Regular physical activity and a healthy body weight.Getting regular exercise and controlling your weight can lower your risk for osteoporosis and heart disease.
• Treatments for associated conditions. If you have a condition that is related to POI, it is important to treat that as well. Treatments may involve medicines and hormones.

NIH: National Institute of Child Health and Human Development

Some people think that tanning gives them a healthy glow. But tanning, either outdoors or indoors with a tanning bed, is not healthy at all. It exposes you to harmful rays and puts you at risk for health problems such as melanoma and other skin cancers.

Sunlight travels to earth as a mixture of both visible and invisible rays. Some of the rays are harmless to people. But one kind, ultraviolet (UV) rays, can cause problems. They are a form of radiation. UV rays do help your body make vitamin D, but too much exposure damages your skin. Most people can get the vitamin D that they need with only about 5 to 15 minutes of sun exposure two to three times a week.

There are three types of UV rays. Two of them, UVA and UVB, can reach the earth's surface and affect your skin. Using a tanning bed also exposes you to UVA and UVB.

UVB rays can cause sunburn. UVA rays can travel more deeply into the skin than UVB rays. When your skin is exposed to UVA, it tries to protect itself from further damage. It does this by making more melanin, which is the skin pigment that makes your skin darker. That's what gives you a tan. This means that your tan is a sign of skin damage.

Since tanning means overexposure to UV rays, it can damage your skin and cause health problems such as:

• Premature skin aging, which can cause your skin to become thickened, leathery, and wrinkled. You may also have dark spots on your skin. These happen because long-term exposure to UV rays makes your skin less elastic. The more sun exposure you have, the earlier your skin ages.
• Skin cancers, including melanoma. This can happen because the UV light damages the DNA of your skin cells and interferes with your body's ability to fight the cancer.
• Actinic keratosis, a thick, scaly patch of skin that usually forms on areas exposed to the sun, such as the face, scalp, back of the hands, or chest. It can eventually become cancerous.
• Eye damage, including cataracts and photokeratitis (snow blindness)
• A weakened immune system, which can increase your sensitivity to sunlight, decrease the effects of vaccines, and cause you to have reactions to certain medicines.

• Limit sun exposure. Try to stay out of the sun between 10 a.m. and 4 p.m., when its rays are strongest. But remember that you still get sun exposure when you are outside on cloudy days or are in the shade.
• Use sunscreen with sun protective factor (SPF) 15 or higher. It should also be a broad-spectrum sunscreen, which means that it gives you both UVA and UVB protection. If you have very light skin, use SPF 30 or higher. Apply sunscreen 20-30 minutes before going outside and reapply it at least every 2 hours.
• Wear sunglasses that block both UVA and UVB rays. Wrap-around sunglasses work best because they block UV rays from sneaking in from the side.
• Wear a hat. You can get the best protection with a wide-brimmed hat that is made out of a tightly woven fabric, such as canvas.
• Wear protective clothing such as long-sleeved shirts and long pants and skirts. Clothes made from tightly woven fabric offer the best protection.

It is also important to check your skin once a month. If you do see any new or changing spots or moles, go see your health care provider.

Indoor tanning is not better than tanning in the sun; it also exposes you to UV rays and damages your skin. Tanning beds use UVA light, so they expose you to a higher concentration of UVA rays than you would get by tanning in the sun. Tanning lights also expose you to some UVB rays.

Some people think that getting a "base tan" in a tanning salon can protect you when you go in the sun. But a "base tan" causes damage to your skin and will not prevent you from getting sunburn when you go outside.

Indoor tanning is particularly dangerous for younger people. You have a higher risk of melanoma if you started doing indoor tanning while you were a teen or young adult.

Some research shows that frequent tanning may even be addictive. This can be dangerous because the more often you tan, the more damage you do to your skin.

There are other ways to look tan, but they are not all safe:

• Tanning pills have a color additive that turns your skin orange after you take them. But they can be dangerous and are not approved by the Food and Drug Administration (FDA).
• Sunless tanners have no known risk for skin cancer, but you do have to be careful. Most spray tans, lotions, and gels use DHA, a color additive that makes your skin look tan. DHA is considered safe for use on the outside of your body by the FDA. You need to make sure it doesn't get into your nose, eyes, or mouth. If you use a spray tan, be careful not to breathe in the spray. Also, remember that these "tans" do not protect you from UV rays when you go outside.