Vitamin D

Other Names

  • Vitamin D2 (Ergocalciferol)
  • Vitamin D3 (Cholecaciferol)
  • Sunshine vitamin
  • Alfacalcidol: 1-alpha-hydroxycholecalciferol, 1-alpha-hydroxycholécalciférol, 1 alpha (OH)D3.
  • Calcifediol: 25-HCC, 25-hydroxycholecalciferol, 25-hydroxycholécalciferol , 25-hydroxyvitamin D3, 25-hydroxyvitamine D3, 25-OHCC, 25-OHD3, Calcifédiol.
  • Calcipotriene : Calcipotriène, Calcipotriol.
  • Calcitriol: 1,25-DHCC, 1,25-dihydroxycholecalciferol, 1,25-dihydroxycholécalciférol, 1,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamine D3, 1,25-diOHC, 1,25(0H)2D3.
  • Cholecalciferol: 7-déhydrocholestérol Activé, Activated 7-dehydrocholesterol, Cholécalciférol, Colecalciferol, Colécalciférol, Vitamin D3.
  • Dihydrotachysterol: DHT, Dihydrotachystérol, dihydrotachysterol 2, dichysterol, Vitamine D3.
  • Ergocalciferol: Activated Ergosterol, Calciferol, Ergocalciférol, Ergocalciferolum, Ergostérol Activé, Ergostérol Irradié, Irradiated Ergosterol, Viosterol, Viostérol, Vitamin D2, Vitamine D2.
  • Paricalcitol: 19-nor-1,25-dihydroxyvitamin D2, 19-nor-1,25-dihydroxyvitamine D2, Paracalcin.
  • Fat-Soluble Vitamin, Vitamina D, Vitamine D, Vitamine Liposoluble, Vitamine Soluble dans les Graisses.

Function

  • Vitamin D is a fat-soluble vitamin which is stored in the body's fatty tissue.
  • Vitamin D helps the body absorb calcium.
  • Calcium and phosphate are two minerals that are essential for normal bone formation.
  • Throughout childhood, the body uses these minerals to produce bones.
  • If you do not get enough calcium, or if your body does not absorb enough calcium from your diet, bone production and bone tissues may suffer.
  • Vitamin D deficiency can lead to osteoporosis in adults or rickets in children.

Dietary Sources

  • The body makes vitamin D when the skin is directly exposed to the sun.
  • That is why it is often called the "sunshine" vitamin.
  • Most people meet at least some of their vitamin D needs this way.
  • Very few foods naturally contain vitamin D. As a result, many foods are fortified with vitamin D. Fortified means that vitamins have been added to the food.
  • Fatty fish (such as tuna, salmon, and mackerel) are among the best sources of vitamin D.
  • Beef liver, cheese, and egg yolks provide small amounts.
  • Mushrooms provide some vitamin D. The vitamin D content is also being boosted by exposure to some commercially available mushrooms to ultraviolent light.
  • Most milk is fortified with 400 IU vitamin D per quart.
  • Foods made from milk, such as cheese and ice cream, are usually not fortified.
  • Vitamin D is added to many breakfast cereals and to some brands of soy beverages, orange juice, yogurt, and margarine. Check the nutrition fact panel on the food label. 


Supplements

  • It is very hard to get enough vitamin D from food sources alone.
  • Some people may need to take a vitamin D supplement.
  • Vitamin D found in supplements and fortified foods comes in two different forms:
  • - D2 (ergocalciferol)
  • - D3 (cholecalciferol)

Side Effects

  • Excessive vitamin D can make the intestines absorb too much calcium. This may cause high levels of calcium in the blood. High blood calcium can lead to:
  • - Calcium deposits in soft tissues such as the heart and lungs
  • - Confusion and disorientation
  • - Damage to the kidneys
  • - Kidney stones
  • - Nausea
  • - Vomiting
  • - Constipation
  • - Poor appetite
  • - Weakness
  • -Weight loss

Recommendations

  • Ten to 15 minutes of sunshine three times weekly is enough to produce the body's requirement of vitamin D.
  • The sun needs to shine on the skin of your face, arms, back, or legs (without sunscreen).
  • Because exposure to sunlight is a risk for skin cancer, you should use sunscreen after a few minutes in the sun.
  • People who do not live in sunny places may not make enough vitamin D.
  • Skin that is exposed to sunshine indoors through a window will not produce vitamin D.
  • Cloudy days, shade, and having dark-colored skin also cut down on the amount of vitamin D the skin makes.
  • Because vitamin D can come from sun, food, and supplements, the best measure of one’s vitamin D status is blood levels of a form known as 25-hydroxyvitamin D.
  • Blood levels are described either as nanograms per milliliter (ng/mL) or nanomoles per liter (nmol/L), where 0.4 ng/mL = 1 nmol/L. 
  • Levels below 30 nmol/L (12 ng/mL) are too low for bone or overall health.
  • Levels above 125 nmol/L (50 ng/mL) are probably too high.
  • Levels of 50 nmol/L or above (20 ng/mL or above) are sufficient for most individuals.
  • The Recommended Dietary Allowance (RDA) for vitamins reflects how much of each vitamin most people should get on a daily basis.
  • The RDA for vitamins may be used as goals for each person.
  • How much of each vitamin you need depends on your age and gender. Other factors, such as pregnancy and your health, are also important.

Infants (adequate intake of vitamin D)

  • 0 - 6 months: 400 IU (10 micrograms (mcg) per day)
  • 7 - 12 months: 400 IU (10 mcg/day)

Children

  • 1 - 3 years: 600 IU (15 mcg/day)
  • 4 - 8 years: 600 IU (15 mcg/day)

Older children and adults

  • 9 - 70 years: 600 IU (15 mcg/day)
  • Adults over 70 years: 800 IU (20 mcg/day)
  • Pregnancy and breast-feeding
    • 600 IU (15 mcg/day)
    • In general, people over age 50 need higher amounts of vitamin D than younger people
    • Ask your health care provider which amount is best for you.
    • Vitamin D toxicity almost always occurs from using too many supplements.

    Safe upper limit for vitamin D

    • 1,000 to 1,500 IU/day for infants
    • 2,500 to 3,000 IU/day for children 1 - 8 years
    • 4,000 IU/day for children 9 years and older, adults, and pregnant and breast-feeding teens and women

    One microgram of cholecalciferol (D3) = 40 IU of vitamin D


    Recommended Use

    • Vitamin D is used for preventing and treating rickets, a disease that is caused by not having enough vitamin D (vitamin D deficiency).
    • Vitamin D is also used for treating:
      • Weak bones (osteoporosis)
      • Bone pain (osteomalacia)
      • Bone loss in people with a condition called hyperparathyroidism, and an inherited disease (osteogenesis imperfecta) in which the bones are especially brittle and easily broken.
    • Vitamin D is used for preventing falls and fractures in people at risk for osteoporosis,
    • Vitamin D is used for low calcium and bone loss (renal osteodystrophy) in people with kidney failure.
    • Vitamin D is used for conditions of the heart and blood vessels, including high blood pressure and high cholesterol.
    • Vitamin D is used for diabetes, obesity, muscle weakness, multiple sclerosis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), asthma, bronchitis, premenstrual syndrome (PMS), and tooth and gum disease.
    • Vitamin D may be used for skin conditions including vitiligo, scleroderma, psoriasis, actinic keratosis, and lupus vulgaris.
    • Vitamin D used for boosting the immune system, preventing autoimmune diseases, and preventing cancer.
    • Since vitamin D is involved in regulating the levels of minerals such as phosphorous and calcium, it is used for conditions caused by low levels of phosphorous (familial hypophosphatemia and Fanconi syndrome) and low levels of calcium (hypoparathyroidism and pseudohypoparathyroidism).
    • Vitamin D in forms known as calcitriol or calcipotriene is applied directly to the skin for a particular type of psoriasis.

    Effectiveness of Vitamin D

    • 1- Hypophosphatemia (low levels of phosphate in the blood)
    • Taking vitamin D (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.
    • 2- Fanconi Syndrome (low levels of phosphate in the blood)
    • Taking vitamin D (ergocalciferol) by mouth is effective for treating low levels of phosphate in the blood due to a disease called Fanconi syndrome.
    • 3- Low blood calcium levels due to low parathyroid hormone levels.
    • Low levels of parathyroid hormone can cause calcium levels to become too low.
    • Taking vitamin D (dihydrotachysterol, calcitriol, or ergocalciferol) by mouth is effective for increasing calcium blood levels in people with low parathyroid hormone levels.
    • 4- Osteomalacia (softening of the bones).
    • Taking vitamin D (cholecalciferol) is effective for treating softening of the bones. Also, taking vitamin D (calcifediol) is effective for treating softening of the bones due to liver disease.
    • In addition, taking vitamin D (ergocalciferol) is effective for treating softening of the bones caused by medications or poor absorption syndromes.
    • 5- Psoriasis
    • Applying vitamin D or calcipotriene (a synthetic form of vitamin D) to the skin treats psoriasis in some people.
    • Applying vitamin D to the skin together with cream containing drugs called corticosteroids seems to be more effective for treating psoriasis than using just vitamin D or the corticosteroid creams alone.
    • 6- Renal Osteodystrophy (a bone disorder which occurs in people with kidney failure)
    • Taking vitamin D (calcifediol) by mouth manages low calcium levels and prevents bone loss in people with kidney failure.
    • Vitamin D does not appear to reduce the risk of death or bone pain in people with kidney failure.
    • 7- Rickets
    • Vitamin D is effective for preventing and treating rickets.
    • A specific form of vitamin D, calcitriol, should be used in people with kidney failure.
    • 8- Vitamin D deficiency
    • Vitamin D is effective for preventing and treating vitamin D deficiency.

    Vitamin D may be effective for:

    • 1- Bone loss in people taking drugs called corticosteroids
    • Taking vitamin D (calcifediol, cholecalciferol, calcitriol, or alfacalcidol) by mouth prevents bone loss in people taking drugs called corticosteroids.
    • Taking vitamin D alone or with calcium seems to improve bone density in people with existing bone loss caused by using corticosteroids.
    • 2- Preventing falls in older people
    • People who do not have enough vitamin D tend to fall more often than people who do.
    • Taking a vitamin D supplement seems to reduce the risk of falling by up to 22%
    • Higher doses of vitamin D are more effective than lower doses.
    • Taking 800 IU of vitamin D may reduce the risk of falling, but lower doses do not.
    • Vitamin D, in combination with calcium, but not calcium alone, may prevent falls by decreasing body sway and blood pressure.
    • Taking vitamin D plus calcium seems to prevent falls more significantly in women than men and in older people living in hospitals or residential care facilities than those living in community dwellings.
    • 3- Osteoporosis (weak bones)
    • Taking a specific form of vitamin D called cholecalciferol (vitamin D3) along with calcium seems to help prevent bone loss and bone breaks.
    • 4- Cancer
    • People who take a high-dose vitamin D supplement plus calcium might have a lower risk of developing certain types of cancer.
    • Taking vitamin D alone does not appear to reduce the risk of cancer.
    • 5- Cavities
    • Taking vitamin D3 (cholecalciferol) reduces the risk of cavities by 49% and vitamin D2 (ergocalciferol) reduces the risk by 36% in infants, children and adolescents.
    • 6- Bone loss caused by having too much parathyroid hormone (hyperparathyroidism)
    • Taking vitamin D (cholecalciferol) by mouth seems to reduce parathyroid hormone levels and bone loss in women with a condition called hyperparathyroidism.
    • 7- Multiple sclerosis (MS)
    • Taking vitamin D can reduce the risk of developing MS in women by up to 40%.
    • Taking at least 400 IU daily, the amount typically found in a multivitamin supplement, seems to work the best.
    • 8- Respiratory infections
    • Taking a vitamin D supplement during winter by school children may reduce the chance of developing seasonal flu.
    • Taking a vitamin D supplement may reduce the chance of an asthma attack triggered by a cold or other respiratory infection.
    • Children with low levels of vitamin D have a higher chance of developing a respiratory infection such as the common cold or flu.
    • Vitamin D may only have an effect on respiratory infections in children. It does not appear to provide the same benefits in adults.
    • 9- Rheumatoid arthritis
    • Older women who consume more vitamin D from foods or supplements may be at a lower risk of developing rheumatoid arthritis.
    • 10- Tooth loss
    • Oral calcium and vitamin D may prevent tooth loss in elderly people.
    • 11- Weight loss
    • People with lower vitamin D levels are more likely to be obese than those with higher levels.
    • Women taking calcium plus vitamin D are more likely to lose weight and maintain their weight. However, this benefit is mainly in women who did not consume enough calcium before they started taking supplements.
    • 12- Myelodysplastic syndrome (a blood cell disease)
    • Oral vitamin D (calcitriol or calcifediol) by mouth may help people with myelodysplastic syndrome.

    • 13- Gum disease
    • Higher blood levels of vitamin D seem to be linked with a reduced risk of gum disease in people 50 years of age or older. However, this does not seem to be true for adults younger than 50 years.
    • 14- Premenstrual syndrome (PMS)
    • Consuming more vitamin D from the diet might help to prevent PMS or reduce symptoms. Taking vitamin D supplements does not seem to prevent PMS. However taking vitamin D plus calcium seems to reduce PMS symptoms.
    • 15- Proximal myopathy (muscle disease)
    • Oral vitamin D (ergocalciferol) or injecting vitamin D into the muscle may help treat a muscle disease associated with vitamin D deficiency.
    • 16- Seasonal depression (seasonal affective disorder)
    • Vitamin D improves symptoms of seasonal depression.
    • 17- Seborrheic keratosis (non-cancerous wart-like growths on the skin)
    • Applying vitamin D3 (cholecalciferol) to the skin might reduce tumor size in some people with seborrheic keratosis.
    • 18- Muscle pain caused by medications called statins
    • Oral vitamin D supplements can decrease symptoms of muscle pain in people taking statin drugs.
    • 19- Vaginal atrophy
    • Oral vitamin D supplements for a least one year may improve the surface of the vaginal wall. However, it does not seem to improve symptoms of vaginal atrophy.
    • 20- Warts
    • Applying Maxacalcitol, which comes from vitamin D3, to the skin, can reduce viral warts in people with weakened immune systems.

    Safety

    • Vitamin D is LIKELY SAFE when taken by mouth or given as a shot into the muscle in recommended amounts.
    • Most people do not commonly experience side effects with vitamin D, unless too much is taken.
    • Some side effects of taking too much vitamin D include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, vomiting, and others.
    • Taking vitamin D for long periods of time in doses higher than 4000 units daily is POSSIBLY UNSAFE and may cause excessively high levels of calcium in the blood.
    • However, much higher doses are often needed for the short-term treatment of vitamin D deficiency. This type of treatment should be done under the supervision of a healthcare provider.

    Precautions & Warnings

  • Pregnancy and breast-feeding
    • Vitamin D is safe during pregnancy and breast-feeding when used in daily amounts below 4000 units.
    • Do not use higher doses.
    • Vitamin D may be unsafe when used in higher amounts during pregnancy or while breast-feeding.
    • Using higher doses might cause serious harm to the infant.

  • Kidney disease
    • Vitamin D may increase calcium levels and increase the risk of “hardening of the arteries” in people with serious kidney disease.
    • This must be balanced with the need to prevent renal osteodystrophy, a bone disease that occurs when the kidneys fail to maintain the proper levels of calcium and phosphorus in the blood.
    • Calcium levels should be monitored carefully in people with kidney disease.

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

  • Atherosclerosis “hardening of the arteries”
    • Taking vitamin D could make this condition worse, especially in people with kidney disease.

  • Sarcoidosis
    • Vitamin D may increase calcium levels in people with sarcoidosis.
    • This could lead to kidney stones and other problems.
    • Use vitamin D cautiously.

  • Histoplasmosis
    • Vitamin D may increase calcium levels in people with histoplasmosis.
    • This could lead to kidney stones and other problems.
    • Use vitamin D cautiously.

  • Hyperparathyroidism (over-active parathyroid gland)
    • Vitamin D may increase calcium levels in people with hyperparathyroidism.
    • Use vitamin D cautiously.

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

    9- Tuberculosis

      • Vitamin D might increase calcium levels in people with tuberculosis.
      • This might result in complications such as kidney stones.

    Interactions with Medications

    Moderate Vitamin D – Drug Interactions

    “Be cautious with this combination”

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

  • Atorvastatin (Lipitor)
    • Vitamin D might decrease the amount of atorvastatin (Lipitor) that enters the body.
    • This might decrease how well atorvastatin (Lipitor) works.

  • Calcipotriene (Dovonex)
    • Calcipotriene is a drug that is similar to vitamin D.
    • Taking vitamin D along with calcipotriene (Dovonex) might increase the effects and side effects of calcipotriene (Dovonex).
    • Avoid taking vitamin D supplements if you are taking calcipotriene (Dovonex).

  • Digoxin (Lanoxin)
    • Vitamin D helps your body absorb calcium.
    • Calcium can affect the heart.
    • Digoxin (Lanoxin) is used to help your heart beat stronger.
    • Taking vitamin D along with digoxin (Lanoxin) may increase the effects of digoxin (Lanoxin) and lead to an irregular heartbeat.
    • If you are taking digoxin (Lanoxin), talk to your doctor before taking vitamin D supplements.

  • Diltiazem (Cardizem, Dilacor, Tiazac)
    • Vitamin D helps your body absorb calcium.
    • Calcium can affect your heart.
    • Diltiazem (Cardizem, Dilacor, Tiazac) can also affect your heart.
    • Taking large amounts of vitamin D along with diltiazem (Cardizem, Dilacor, Tiazac) may decrease the effectiveness of diltiazem.

  • Medications changed by the liver (Cytochrome P450 3A4 (CYP 3A4) substrates)
    • Some medications are changed and broken down by the liver.
    • Vitamin D may increase how quickly the liver breaks down some medications.
    • Taking vitamin D along with some medications may decrease the effectiveness of some medications.
    • Before taking vitamin D, talk to your health care provider if you are taking any medications that are changed by the liver.
    • Some of these medications changed by the liver include:
      • Lovastatin (Mevacor)
      • Clarithromycin (Biaxin)
      • Cyclosporine (Neoral, Sandimmune)
      • Diltiazem (Cardizem)
      • Estrogens (Premarin)
      • Indinavir (Crixivan)
      • Triazolam (Halcion)
      • Others

  • Verapamil (Calan, Covera, Isoptin, Verelan)
    • Vitamin D helps your body absorb calcium.
    • Calcium can affect the heart.
    • Verapamil (Calan, Covera, Isoptin, Verelan) can also affect the heart.
    • Do not take large amounts of vitamin D if you are taking verapamil (Calan, Covera, Isoptin, Verelan).

  • Water pills (Thiazide diuretics)
    • Vitamin D helps your 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" may cause to be too much calcium in the body.
    • This could cause serious side effects including kidney problems.
    • Some of these "water pills" include:

    - Chlorothiazide (Diuril)

    - Hydrochlorothiazide (HydroDIURIL, Esidrix)

    - Indapamide (Lozol)

    - Metolazone (Zaroxolyn)

    - Chlorthalidone (Hygroton)


    Minor Vitamin D – Drug Interactions

    “Be watchful with this combination”

  • Cimetidine (Tagamet)
    • The body changes vitamin D into a form that it can use.
    • Cimetidine (Tagamet) might decrease how well the body changes vitamin D.
    • This may decrease how well vitamin D works.
    • However, this interaction probably isn't important for most people.

  • Heparin
    • Heparin slows blood clotting and can increase the risk of breaking a bone when used for a long period of time.
    • People taking these medications should eat a diet rich in calcium and vitamin D.

  • Low molecular weight heparins (LMWHs)
    • Some medications called low molecular weight heparins can increase the risk of breaking a bone when used for a long periods of time.
    • People taking these medications should eat a diet rich in calcium and vitamin D.
    • These drugs include:
      • Enoxaparin (Lovenox)
      • Dalteparin (Fragmin)
      • Tinzaparin (Innohep).

    Interactions with Herbs and Supplements


  • Magnesium
    • Taking vitamin D can raise the level of magnesium in people who have low magnesium and low vitamin D levels.
    • In people with normal magnesium levels, this doesn't seem to happen.

    Interactions with Foods

    • There are no known interactions with foods.

    Recommended Dosage
    Oral Vitamin D Dosage

        1. For preventing osteoporosis and fractures in older adults
    • 400-1000 IU daily
    • Some experts recommended higher doses of 1000-2000 IU daily.
    • 2- For preventing falls
    • 800-1000 IU/day in combination with calcium 1000-1200 mg/day.
    • 3- For preventing multiple sclerosis (MS)
    • Long-term consumption of at least 400 IU per day, mainly in the form of a multivitamin supplement.
    • 4- For preventing all cancer types
    • Calcium 1400-1500 mg/day plus vitamin D3 (cholecalciferol) 1100 IU/day in postmenopausal women.
    • 5- For muscle pain caused by medications called "statins"
    • Vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol) 50,000 units once a week or 400 IU daily.
    • 6- For preventing the flu
    • Vitamin D (cholecalciferol) 1200 IU daily.

    Most vitamin supplements contain only 400 IU (10 mcg) vitamin D.

    Recommended Daily Allowance (RDA)

    • RDA is an estimate of the amount of vitamin D that meets the needs of most people in the population.
    • The RDA varies based on age as follows:
    • 1-70 years of age, 600 IU daily
    • 71 years and older, 800 IU daily
    • Pregnant and lactating women, 600 IU daily
    Infants ages 0-12 months, an adequate intake (AI) level of 400 IU is recommended.