Table of ContentsView AllTable of ContentsEffect on the BodyHow to Get Vitamin DSigns You Need MoreSide Effects of High LevelsDosing Vitamin DFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Effect on the Body
How to Get Vitamin D
Signs You Need More
Side Effects of High Levels
Dosing Vitamin D
Frequently Asked Questions
Vitamin D, also known as calciferol, is a fat-soluble vitamin essential for physical and mental health. The two primary forms of vitamin D are vitamin D2 (ergocalciferol), found in plants, andvitamin D3(cholecalciferol), found in animal tissues.
Vitamin D is essential for immune system function and bone health. It may also influence mood regulation and reduce the risk of several chronic health conditions, but more research is needed to better understand vitamin D benefits.
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. Whenchoosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
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Effect of Vitamin D on the Body
Vitamin D helps the body retain and absorb calcium and phosphorus, which are important for building and maintaininghealthy bonesand teeth. Your nerves need vitamin D to carry messages between your brain and body, your immune system needs it to fight off bacteria and viruses, and your muscles need it to move.
Vitamin D deficiency can lead to decreased bone density, which can eventually causeosteoporosisand broken bones. In adults, a severe deficiency can also result inosteomalacia, which causes muscle and bone pain and weakness.
While more research is needed, several studies link vitamin D deficiency to several health conditions, including:
Vitamin D and ChildrenVitamin D is important for children because it helps build strong bones and protects againstrickets. This rare condition affects bone development, primarily in the first two years of life. The vitamin also protects against broken bones in children and teens.
Vitamin D and Children
Vitamin D is important for children because it helps build strong bones and protects againstrickets. This rare condition affects bone development, primarily in the first two years of life. The vitamin also protects against broken bones in children and teens.
Different Ways to Get Vitamin D
Your body makes vitamin D when it’s exposed directly tosunlight. However, prolonged sun exposure is advised against because it can increase your risk of other ailments, such as premature aging andskin cancer. Additionally, most people get less vitamin D during the winter months because of insufficient exposure to sunlight.
This makes it necessary to get vitamin D from other sources. Because vitamin D is not naturally present in many foods, fortified foods provide most of the vitamin D in the American diet.
Dietary sources of vitamin D include:
What Are Signs You Need Vitamin D?
Vitamin D deficienciesare relatively common throughout the United States. Many people with vitamin D deficiency have no symptoms. However, a deficiency may cause the following symptoms:
Risk Factors
You may have a greater risk of developing vitamin D deficiency if you take medications that interfere with vitamin D metabolism or if you have the following conditions:
Your healthcare provider can order a blood test to measure the level of vitamin D in your blood. If your levels are low, your provider will likely recommend taking avitamin D supplementto correct the deficiency.
Side Effects of High Vitamin D Levels
Vitamin D toxicityis unlikely to occur from diet or excess sun exposure since your body can control the amount of vitamin D it makes from the sun. In most cases, toxicity occurs due to theoveruse of vitamin D supplements.
The main side effect of vitamin D toxicity is a condition calledhypercalcemia, in which too much calcium builds up in the blood, causing symptoms like:
Extremely high vitamin D levels can cause more serious side effects, includingirregular heartbeat, kidney failure, and death.
Vitamin D intake is measured in international units (IU) and micrograms (mcg). The amount of vitamin D you need daily depends on your age and other health factors.
The daily vitamin D requirements are:
When to Take Vitamin D: Morning or Night?
Though some anecdotal reports claim that taking vitamin D before bed suppressesmelatoninproduction and negatively impacts sleep quality, there is no solid evidence to support this theory. You can take vitamin D supplements any time of the day.
However, because vitamin D is afat-soluble vitamin, it is best taken with meals or snacks containing fat, which helps your body better absorb the vitamin.
Summary
Vitamin D is involved in many bodily functions and plays a vital role in immune health and maintaining healthy bones and teeth. It may also help improve mood and protect against certain diseases. Vitamin D is found in some food products, such as fatty fish and fortified dairy foods.
Frequently Asked QuestionsVitamin D deficiency can cause fatigue. Studies have shown that vitamin D supplementation may improve fatigue in otherwise healthy individuals with vitamin D deficiency.It usually takes a few months to raise vitamin D levels with consistent supplementation.Symptoms of low vitamin D levels can include fatigue, muscle pain or weakness, bone pain, depression, and cognitive impairment.Learn MoreWhat is Vitamin D deficiency?
Vitamin D deficiency can cause fatigue. Studies have shown that vitamin D supplementation may improve fatigue in otherwise healthy individuals with vitamin D deficiency.
It usually takes a few months to raise vitamin D levels with consistent supplementation.
Symptoms of low vitamin D levels can include fatigue, muscle pain or weakness, bone pain, depression, and cognitive impairment.Learn MoreWhat is Vitamin D deficiency?
Symptoms of low vitamin D levels can include fatigue, muscle pain or weakness, bone pain, depression, and cognitive impairment.
Learn MoreWhat is Vitamin D deficiency?
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mohammad S, Mishra A, Ashraf MZ.Emerging role of vitamin d and its associated molecules in pathways related to pathogenesis of thrombosis.Biomolecules. 2019;9(11):649. doi:10.3390/biom9110649National Institutes of Health.Vitamin D : Consumer fact sheet.Cheng Y, Huang Y, Huang W.The effect of vitamin D supplement on negative emotions: A systematic review and meta‐analysis.Depress Anxiety. 2020;37(6):549-564. doi:10.1002/da.23025MedlinePlus.Vitamin D deficiency.American Academy of Pediatrics.Vitamin D for babies, children & adolescents.National Institutes of Health.Vitamin D: Health professional.Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial.Medicine. 2016;95(52):e5353. doi:10.1097/MD.0000000000005353Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue.Medicine (Baltimore). 2016;95(52):e5353. doi: 10.1097/MD.0000000000005353
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mohammad S, Mishra A, Ashraf MZ.Emerging role of vitamin d and its associated molecules in pathways related to pathogenesis of thrombosis.Biomolecules. 2019;9(11):649. doi:10.3390/biom9110649National Institutes of Health.Vitamin D : Consumer fact sheet.Cheng Y, Huang Y, Huang W.The effect of vitamin D supplement on negative emotions: A systematic review and meta‐analysis.Depress Anxiety. 2020;37(6):549-564. doi:10.1002/da.23025MedlinePlus.Vitamin D deficiency.American Academy of Pediatrics.Vitamin D for babies, children & adolescents.National Institutes of Health.Vitamin D: Health professional.Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial.Medicine. 2016;95(52):e5353. doi:10.1097/MD.0000000000005353Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue.Medicine (Baltimore). 2016;95(52):e5353. doi: 10.1097/MD.0000000000005353
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Mohammad S, Mishra A, Ashraf MZ.Emerging role of vitamin d and its associated molecules in pathways related to pathogenesis of thrombosis.Biomolecules. 2019;9(11):649. doi:10.3390/biom9110649National Institutes of Health.Vitamin D : Consumer fact sheet.Cheng Y, Huang Y, Huang W.The effect of vitamin D supplement on negative emotions: A systematic review and meta‐analysis.Depress Anxiety. 2020;37(6):549-564. doi:10.1002/da.23025MedlinePlus.Vitamin D deficiency.American Academy of Pediatrics.Vitamin D for babies, children & adolescents.National Institutes of Health.Vitamin D: Health professional.Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial.Medicine. 2016;95(52):e5353. doi:10.1097/MD.0000000000005353Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue.Medicine (Baltimore). 2016;95(52):e5353. doi: 10.1097/MD.0000000000005353
Mohammad S, Mishra A, Ashraf MZ.Emerging role of vitamin d and its associated molecules in pathways related to pathogenesis of thrombosis.Biomolecules. 2019;9(11):649. doi:10.3390/biom9110649
National Institutes of Health.Vitamin D : Consumer fact sheet.
Cheng Y, Huang Y, Huang W.The effect of vitamin D supplement on negative emotions: A systematic review and meta‐analysis.Depress Anxiety. 2020;37(6):549-564. doi:10.1002/da.23025
MedlinePlus.Vitamin D deficiency.
American Academy of Pediatrics.Vitamin D for babies, children & adolescents.
National Institutes of Health.Vitamin D: Health professional.
Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial.Medicine. 2016;95(52):e5353. doi:10.1097/MD.0000000000005353
Nowak A, Boesch L, Andres E, et al.Effect of vitamin D3 on self-perceived fatigue.Medicine (Baltimore). 2016;95(52):e5353. doi: 10.1097/MD.0000000000005353
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