Why you need vitamin D
![Vitamin D is an important hormone in your body that helps you regulate your calcium and phosphorus balance and bone density. The best way to know if you're getting enough vitamin D is if you get the recommended amount in your diet.](https://images.medicinenet.com/images/article/main_image/benefits-of-vitamin-d.jpg?output-quality=75)
Vitamin D is an important hormone in your body that helps you regulate your calcium and phosphorus balance and bone density.
You need vitamin D to build healthy, strong bones and teeth. It also helps control infections, lowers cancer cell growth, and heals inflammation.
Vitamin D is also important for a healthy immune system. It regulates your immune system activity and studies show it might help boost your natural defenses.
It’s also important for protecting your body from autoimmunity, which happens when your immune system attacks your own tissues and cells.
You get vitamin D mostly from the sun. Sun rays energize cholesterol in your skin, and the cells convert it into a molecule called pre-vitamin D. This goes to your liver and is converted into cholecalciferol and then to your kidneys, where it is converted to the active form of vitamin D called calcitriol.
You can also get vitamin D from fortified foods. Only a few natural foods contain vitamin D, so it is commonly added to some foods like cereals, milk, and orange juice. When you consume vitamin D, you get an inactive form, which your liver and kidneys convert to the active form.
The recommended daily allowance for adults age 19 years and older is 600 international units (IU) daily. If you’re over 70 years of age, you should get 800 IU of vitamin D every day.
Why you don’t get enough vitamin D
Vitamin D deficiency is most commonly caused by a lack of sun exposure. The sun is the most natural way to get vitamin D, but it’s hard to get enough because you also need to protect your skin from sun damage. Some groups of people tend not to get enough vitamin D. Those most prone to deficiencies include people who:
- Live in cold climates and spend a lot of time inside
- Work inside
- Live in long-term care facilities
- Wear sunscreen
- Wear long, protective clothing
Older people and people with darker skin tones are also likely to get less vitamin D from the sun. Older people have less cholesterol in the skin and people with darker skin tones have more melanin, which slows down UV ray absorption. Both of these stop the sun from making vitamin D in older or darker skin tones.
Some health conditions can cause problems absorbing vitamin D and can lead to low vitamin D levels. These conditions include:
- Celiac disease
- Ulcerative colitis
- Crohn’s disease
- Lactose intolerance
- Liver disease
- Kidney disease
- Pancreatitis
- Cystic fibrosis
Low vitamin D symptoms
Insufficient vitamin D can cause different symptoms — including:
- Muscle aches
- Muscle weakness
- Muscle spasms — called tetany
- Bone pain
- Rickets in children
- Irregular bone growth in children
- Weakened bones
- Fractures
- Softened bones — called osteomalacia
- Loss of calcium
- Getting sick a lot
- Inflammation
People with autoimmune diseases are likely to have low vitamin D, but how this happens is still unclear.
The symptoms of low vitamin D can look like other health problems, so it’s important to talk to your doctor. They can do blood tests to check your levels. If you have severely low levels, you might need to take a higher amount to correct the deficiency.
Are you getting enough vitamin D?
Some doctors recommend that you expose your skin to the sun for 5 to 15 minutes three times a week to prevent vitamin D deficiency. Some people might need more time to get enough vitamin D, but this isn’t recommended. Too much time in the sun without protection can cause skin cancer.
So the best way to know if you’re getting enough vitamin D is if you get the recommended amount in your diet. These recommendations will help you reach the proper level:
- Drink cow’s milk
- Drink fortified non-dairy milk
- Eat fortified foods
- Take a vitamin D supplement
To make sure you’re getting enough from food, you’ll need to track your intake, calculate, and add in other sources. For example, one serving of fortified cereal usually has only about 40 to 50 IUs of vitamin D. This means you’ll have to eat or drink a few other foods — or take a supplement — to make sure you’re getting enough.
Vitamin D is also fat-soluble. To properly absorb vitamin D supplements, have some healthy fat with your meal.
If you need help with your diet, talk to a doctor or a nutritionist. They can also help you find the right vitamin D supplement for you.
![](https://images.medicinenet.com//images/slideshow/amazing_vitamin_d_s1_wonder_vitamin.jpg)
SLIDESHOW
Vitamin D Deficiency: How Much Vitamin D Is Enough? See SlideshowHarvard T.H. Chan School of Public Health: "Vitamin D."
Journal of the Academy of Nutrition and Dietetics: "Dietary fat increases vitamin D-3 absorption."
Merck Manual Consumer Version: "Vitamin D Deficiency."
Oregon State University Linus Pauling Institute: "Vitamin D."
St. Luke’s Health: "4 Signs You Have a Vitamin D Deficiency."
University of Rochester Medical Center: "Vitamin D."
Top How Do You Know if You're Getting Enough Vitamin D Related Articles
Does Vitamin D Protect Against COVID-19?
COVID-19 or coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It manifests as mild to moderate respiratory illness in most people who may not require any special treatment. Certain high-risk groups, such as older people and people with underlying health conditions (chronic respiratory diseases, diabetes, cancer and cardiovascular diseases), are more likely to get seriously ill.How Do I Know If I Am Getting Enough Vitamin D?
Vitamin D is an important nutrient that helps your body function properly. The best way to find out if you are getting enough vitamin D through your lifestyle and diet is to take the 25-hydroxy vitamin D blood test.Lactose Intolerant? How to Get Calcium and Vitamin D
See how to eat right when dairy gives you stomach problems. WebMD shows you ways to get calcium and vitamin D through lactose-free milk, foods, and the sun.multivitamins
Multivitamins are a combination of vitamins, minerals, and other nutrients used to supplement nutritional deficiency and help maintain good health and normal functioning of the body. Common side effects of multivitamins include nausea, vomiting, abdominal pain, dark stools, and constipation. Do not give adult multivitamin preparations to children. Multivitamins at recommended doses are generally safe for use during pregnancy and breastfeeding. Multivitamins cannot replace a healthy diet.Vitamin D Slideshow
What does vitamin D do? Learn about vitamin D benefits and discover foods that are high in vitamin D. Explore vitamin D deficiency symptoms and the safest ways to get enough vitamin D.panax ginseng
Panax ginseng is an herbal adaptogen, a substance that is believed to help people adapt to and manage stress, anxiety, and fatigue, and is believed to enhance overall health, stamina and cognitive function. Common side effects of panax ginseng include headache, fever (pyrexia), high or low blood pressure (hypertension/hypotension), palpitations, rapid heart rate (tachycardia), breast pain (mastalgia), vaginal bleeding, absence of menstruation (amenorrhea), vomiting, diarrhea, reduced appetite, nervousness, insomnia, mania, euphoria, and swelling (edema). Do not take panax ginseng if you are pregnant.pantothenic acid
Pantothenic acid is vitamin B5, an essential nutrient, which is taken as a supplement to compensate for deficiency. Common side effects of pantothenic acid include headache, weakness/lack of energy (asthenia), muscle pain (myalgia), joint pain (arthralgia), dizziness, flulike illness, sore throat, abdominal pain, nausea, constipation, inflammation of the pancreas (pancreatitis), onset of diabetes mellitus, and others. Consult your doctor if pregnant or breastfeeding.What Are the Symptoms and Causes of Vitamin D Deficiency?
What is vitamin D deficiency? Learn the signs of vitamin D deficiency and what foods you can eat to help prevent vitamin D deficiency.vitamin A
Vitamin A is a supplement used to prevent and treat vitamin A deficiency. Vitamin A supports growth and bone development, vision, reproduction, and the development and maintenance of skin tissue. It may also improve the function of the immune system and prevent some cancers. Common side effects of vitamin A supplements include sticky skin, inflammation of the lips, acne, and facial dermatitis. Vitamin A is generally considered safe to consume during pregnancy or while breastfeeding.Vitamin D Deficiency
Vitamin D deficiency has been linked with rickets, cancer, cardiovascular disease, severe asthma in children and cognitive impairment in older adults. Causes include not ingesting enough of the vitamin over time, having limited exposure to sunlight, having dark skin, and obesity. Symptoms include bone pain and muscle weakness. Treatment for vitamin D deficiency involves obtaining more vitamin D through supplements, diet, or exposure to sunlight.Vitamin D Quiz
What happens to the body when there is a vitamin D deficiency? Take the Vitamin D Quiz to find out what you may be missing.vitamin D
Vitamin D (Ergocalciferol [Vitamin D2], Cholecalciferol [Vitamin D3]) is required for the maintanence for bones and teeth. It works to increase absorption of calcium and to prevent its loss through the kidneys.Vitamins and Calcium Supplements
Vitamins are organic substances that are essential for the proper growth and functioning of the body. Calcium is a mineral essential for healthy bones and is also important for muscle contraction, heart action, and normal blood clotting. Check out the center below for more medical references on vitamins and calcium supplements, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.Vitamins and Supplements: Foods High in Vitamin D
Vitamin D is important for your bones, blood cells, and immune system -- your body's defense against germs. Find out which foods are the best source of this nutrient.What Are the Benefits of Vitamin D?
Vitamin D is an essential nutrient for our bodies. Learn about eight benefits of vitamin D, how to know if you’re getting enough vitamin D, and what to eat to increase vitamin D in your body.What Foods Are Highest in Vitamin D?
What are the foods highest in Vitamin D? Learn about the best sources to make sure this vitamin is included in your diet.What Is a Good Family Multivitamin?
When looking for a good multivitamin for your family, consider one that has the following nutrients: vitamin D, Folate, Vitamin B-12Calcium, Iron, Zinc, and Magnesium.What Is the Test for Vitamin D?
Vitamin D is a fat-soluble vitamin that plays a vital role in calcium absorption to give you healthy and strong bones. The test for measuring vitamin D involves measuring the levels of the vitamin in a blood sample drawn from your vein.What Vitamin Deficiency Causes Ringing in the Ears?
Ringing in the ears has been linked to vitamin B12 and vitamin D deficiencies. Treating an underlying cause of tinnitus such as a vitamin deficiency may help relieve symptoms.