Overview

Vitamin D is an essential vitamin that helps regulate calcium and phosphorus in the body. It also plays a role in maintaining proper bone structure.

There are different forms of vitamin D, including ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Vitamin D is found in fish, eggs, and fortified milk. It's also made in the skin when exposed to sunlight. During periods of sunlight, vitamin D is stored in fat and then released when sunlight is not available.

Vitamin D supplements are commonly used to treat and prevent vitamin D deficiency. People who don't get enough sun and people who are 65 years or older are at risk for deficiency. People also use vitamin D for weak and brittle bones, heart disease, asthma, hay fever, and many other conditions, but there's no good scientific evidence to support many of these uses. There is also no strong evidence to support using vitamin D supplements for COVID-19. But it is important to maintain healthy levels of vitamin D. This can be done by taking 400-1000 IU of vitamin D daily or spending 15-30 minutes in the sun each day.

Uses & Effectiveness ?

Effective for

  • A rare, inherited bone disorder marked by low levels of phosphate in the blood (familial hypophosphatemia). Taking specific forms of vitamin D, called calcitriol or dihydrotachysterol, by mouth along with phosphate supplements is effective for treating bone disorders in people with low levels of phosphate in the blood.
  • Underactive parathyroid (hypoparathyroidism). Taking specific forms of vitamin D, called dihydrotachysterol, calcitriol, or ergocalciferol, by mouth is effective for increasing calcium blood levels in people with low parathyroid hormone levels.
  • Softening of the bones (osteomalacia). Taking vitamin D3 by mouth is effective for treating this condition.
  • A bone disorder that occurs in people with kidney disease (renal osteodystrophy). Taking a specific form of vitamin D, called calcitriol, by mouth helps to manage low calcium levels and prevent bone loss in people with kidney failure.
  • Rickets. Taking vitamin D by mouth is effective for preventing and treating rickets. A specific form of vitamin D, called calcitriol, should be used in people with kidney failure.
  • Vitamin D deficiency. Taking vitamin D by mouth is effective for preventing and treating vitamin D deficiency.

Likely Effective for

  • Bone loss in people taking drugs called corticosteroids. Taking vitamin D by mouth prevents bone loss in people taking drugs called corticosteroids. Also, taking vitamin D alone or with calcium seems to improve bone density in people with existing bone loss caused by using corticosteroids.
  • Weak and brittle bones (osteoporosis). Taking vitamin D3 by mouth along with calcium seems to help prevent bone loss and bone breaks in people with osteoporosis.
  • Psoriasis. Applying vitamin D in the form of calcitriol, calcipotriene, maxacalcitol, or paricalcitol to the skin can help treat plaque-type psoriasis. Applying vitamin D along with corticosteroids seems to work better than applying vitamin D or corticosteroids alone. But taking vitamin D by mouth doesn't seem to help.

Possibly Effective for

  • Cavities. Taking vitamin D2 or D3 by mouth reduces the risk of cavities by 36% to 49% in infants, children, and adolescents.
  • Heart failure. Taking vitamin D by mouth can help reduce the risk of developing heart failure in some people. But it doesn't seem to help patients who already have heart failure.
  • Bone loss in people with overactive parathyroid (hyperparathyroidism-related bone loss). Taking vitamin D3 by mouth seems to reduce parathyroid hormone levels and bone loss in people with a condition called hyperparathyroidism.
  • Infection of the airways. Taking vitamin D by mouth helps prevent respiratory infections in children. But taking vitamin D during pregnancy doesn't seem to reduce the risk of these infections in children after birth. It also doesn't help prevent infections in adults.
  • Preventing tooth loss (tooth retention). Taking calcium and vitamin D3 by mouth appears to prevent tooth loss in elderly people.

Possibly Ineffective for

  • Eczema (atopic dermatitis). Taking vitamin D during pregnancy or giving vitamin D to an infant doesn't seem to reduce the chance that the child will develop eczema.
  • Heart disease. People with low blood levels of vitamin D seem to have a greater chance of developing heart disease. But taking a vitamin D supplement doesn't seem to prevent heart disease, heart attack, stroke, or other serious heart-related events in most people.
  • Critical illness (trauma). Giving vitamin D to people with low vitamin D levels who are in the hospital with a critical illness doesn't make them more likely to live.
  • Fractures. Taking vitamin D by mouth doesn't seem to prevent fractures in older people who do NOT have osteoporosis.
  • High blood pressure. Taking vitamin D by mouth doesn't seem to lower blood pressure in most people with high blood pressure. But it might help people who have very low blood levels of vitamin D.
  • A mental disorder marked by hallucinations and delusion (psychosis). Taking vitamin D by mouth doesn't seem to improve symptoms of psychosis in adults.
  • Prostate cancer. Taking vitamin D by mouth doesn't seem to reduce cancer progression or death from prostate cancer.
  • Tuberculosis. Most research shows that taking vitamin D by mouth doesn't help to cure tuberculosis or make it less severe.
There is interest in using vitamin D for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: Vitamin D is likely safe when taken in recommended amounts. Most people don't experience side effects with vitamin D, unless too much is taken. Some side effects of taking too much vitamin D include weakness, dry mouth, nausea, vomiting, and others. Taking vitamin D for long periods of time in doses higher than 4000 IU (100 mcg) daily is possibly unsafe and may cause very high levels of calcium in the blood.

Special Precautions and Warnings

When taken by mouth: Vitamin D is likely safe when taken in recommended amounts. Most people don't experience side effects with vitamin D, unless too much is taken. Some side effects of taking too much vitamin D include weakness, dry mouth, nausea, vomiting, and others. Taking vitamin D for long periods of time in doses higher than 4000 IU (100 mcg) daily is possibly unsafe and may cause very high levels of calcium in the blood. Pregnancy and breast-feeding: Vitamin D is likely safe during pregnancy and breast-feeding when used in daily amounts below 4000 IU (100 mcg). Do not use higher doses unless instructed by your healthcare provider. Vitamin D is possibly unsafe when used in higher amounts during pregnancy or while breast-feeding. Using higher doses might cause harm to the infant.

Children: Vitamin D is likely safe in children when taken by mouth in recommended amounts. But it is possibly unsafe to take vitamin D in higher doses, long-term. Infants from 0-6 months should not take more than 1000 IU (25 mcg) daily. Infants aged 6-12 months should not take more than 1500 IU (37.5 mcg) daily. Children aged 1-3 years should not take more than 2500 IU (62.5 mcg) daily. Children aged 4-8 years should not take more than 3000 IU (75 mcg) daily. Children aged 9 years and older should not take more than 4000 IU (100 mcg) daily.

Hardening of the arteries (atherosclerosis): Taking vitamin D could make this condition worse, especially in people with kidney disease.

A type of fungal infection called histoplasmosis: Vitamin D might increase calcium levels in people with histoplasmosis. This could lead to kidney stones and other problems. Use vitamin D cautiously.

High levels of calcium in the blood: Taking vitamin D could make this condition worse.

Over-active parathyroid gland (hyperparathyroidism): Vitamin D might increase calcium levels in people with hyperparathyroidism. Use vitamin D cautiously.

Lymphoma: Vitamin D might increase calcium levels in people with lymphoma. This could lead to kidney stones and other problems. Use vitamin D cautiously.

Kidney disease: Vitamin D might increase calcium levels and increase the risk of "hardening of the arteries" in people with serious kidney disease. Calcium levels should be monitored carefully in people with kidney disease.

A disease that causes swelling (inflammation) in body organs, usually the lungs or lymph nodes (sarcoidosis): Vitamin D might increase calcium levels in people with sarcoidosis. This could lead to kidney stones and other problems. Use vitamin D cautiously.

Tuberculosis: Vitamin D might increase calcium levels in people with tuberculosis. This could lead to kidney stones and other problems. Use vitamin D cautiously.

Interactions ?

    Moderate Interaction

    Be cautious with this combination

  • Aluminum interacts with VITAMIN D

    Aluminum is found in most antacids. Vitamin D can increase how much aluminum the body absorbs. This interaction might be a problem for people with kidney disease. Take vitamin D two hours before, or four hours after antacids.

  • Calcipotriene (Dovonex) interacts with VITAMIN D

    Taking vitamin D along with calcipotriene might increase the effects and side effects of calcipotriene.

  • Digoxin (Lanoxin) interacts with VITAMIN D

    Taking vitamin D along with digoxin might increase the effects and side effects of digoxin. If you are taking digoxin, talk to your doctor before taking vitamin D supplements.

  • Diltiazem (Cardizem, others) interacts with VITAMIN D

    Vitamin D helps your body absorb calcium. Calcium can affect the heart. Diltiazem can also affect the heart. Taking large amounts of vitamin D along with diltiazem might decrease the effects of diltiazem.

  • Verapamil (Calan, others) interacts with VITAMIN D

    Vitamin D helps the body absorb calcium. Calcium can affect the heart. Verapamil can also affect the heart. Do not take large amounts of vitamin D if you are taking verapamil.

  • Water pills (Thiazide diuretics) interacts with VITAMIN D

    Vitamin D helps the body absorb calcium. Some "water pills" increase the amount of calcium in the body. Taking large amounts of vitamin D along with some "water pills" might cause too much calcium in the body. This could cause serious side effects, including kidney problems.

  • Atorvastatin (Lipitor) interacts with VITAMIN D

    Vitamin D might decrease how much atorvastatin the body absorbs. Taking vitamin D with atorvastatin might decrease the effects of atorvastatin.

  • Medications changed by the liver (Cytochrome P450 3A4 (CYP 3A4) substrates) interacts with VITAMIN D

    Some medications are changed and broken down by the liver. Vitamin D might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

Dosing

Vitamin D is an essential nutrient. Fish, eggs, and fortified milk are good sources of vitamin D. The amount that should be consumed on a daily basis is called the recommended dietary allowance (RDA). The RDA is 600 IU (15 mcg) daily for people 1-70 years of age and 800 IU (20 mcg) daily for those 71 years and older. While pregnant and breastfeeding, the RDA is 600 IU (15 mcg) daily. In children, the RDA depends on age. Vitamin D is also made in the skin after sun exposure. Spending 15-30 minutes in the sun each day should be enough to maintain normal vitamin D levels for most people.

Most people should not consume more than 4000 IU daily unless under the care of a healthcare provider. Speak with a healthcare provider to find out what dose might be best for a specific condition.
View References

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
© Therapeutic Research Faculty 2020.