I. See also

II. Physiology

  1. Step 1a: Start with 7-Dehydrocholesterol
    1. Skin exposure to sunlight or other ultraviolet light (290-315 nm of UV-B radiation)
    2. This pathway represents 90% of Vitamin D synthesis in humans
  2. Step 1b: Start with Dietary Vitamin D2 or D3
    1. Proceed to step 2 (bypasses sunlight-mediated synthesis pathway)
    2. Typically represents only 10% of Vitamin D source (unless specifically supplemented)
  3. Step 2: Cholecalciferol (Vitamin D3)
    1. Metabolized in liver by Vitamin D3-25 hydroxylase
  4. Step 3: Calcidiol
    1. Metabolized in Kidney by 25-OH-D3-1a hydroxylase
  5. Step 4: Calcitriol (active form of Vitamin D)

III. Pathophysiology

  1. See Serum Calcium for calcium metabolism
  2. Sources
    1. Vitamin D synthesized in skin after exposed to sun
    2. Absorbed from Small Intestine
  3. Vitamin D circulates in blood as Calcidiol
  4. Vitamin D Deficiency seen in:
    1. Homebound elderly
    2. Inhabitants of Northern States
  5. Vitamin D Deficiency related conditions
    1. Children: Rickets
    2. Adults: Osteoporosis

IV. Indications: Vitamin D Supplementation or Replacement

V. Contraindications: Vitamin D Supplementation

  1. Granulomatous disease (e.g. Tuberculosis, Sarcoidosis)
  2. Metastatic bone disease
  3. Williams Syndrome

VI. Preparations: Dietary and Supplement Sources

  1. Fatty Fish (Vitamin D3)
    1. Salmon
    2. Sardines
    3. Fish oils
  2. Eggs
  3. Butter
  4. Liver and other organ meats
  5. Vitamin D Fortified Milk (USA) contains 100 IU per cup
  6. Multi-Vitamin Contains 400 IU Vitamin D per tablet

VII. Signs: Vitamin D Deficiency

  1. See Vitamin D Deficiency
  2. Osteomalacia
  3. Muscular hypotonia

VIII. Signs: Vitamin D Toxicity (related to Hypercalcemia)

  1. Headache
  2. Metallic Taste
  3. Vascular calcinosis or nephrocalcinosis
  4. Pancreatitis
  5. Nausea or Vomiting

IX. Dosing (higher than current RDA)

  1. Children and Adolescents: 400 IU per day
  2. Adults Age 18-50 years: 400-800 IU per day
  3. Adults Age >50 years or Osteoporosis:
    1. Southern regions: 800-2000 IU per day
    2. Northern climates: 2000 IU per day may be required
  4. Expect a 0.4 ng/ml increase for every 40 IU daily of Vitamin D
    1. Expect 4 ng/ml increase from 400 IU daily
    2. Expect 40 ng/ml increase from 4000 IU daily
  5. Vitamin D is fat soluble and is best absorbed with fat in the meal

X. Dosing: Supplementation in Infants and Children under age 2 years

  1. Indications
    1. See Vitamin D Deficiency for risk factors
    2. Breastfed Infants
    3. Children and adolescents consuming <1 Liter (34 oz) Vitamin D Fortified milk daily
  2. Supplements with daily dose of 1 drop (equivalent to 400 IU) for age under 2 years
    1. Carlson Baby D Drops
  3. Supplements with daily dose of 1 ml (equivalent to 400 IU) for age under 2 years
    1. Enfamil Poly-Vi-Sol Multivitamin Supplement drops
    2. Enfamil Poly-Vi-Sol Vitamins A, C and D with Iron
    3. Sunlight Vitamins Just D Infant Vitamin Drops
    4. Twinlab Infant Care Multivitamin Drops with DHA
  4. References
    1. Casey (2010) Am Fam Physician 81(6): 745-50 [PubMed] (or open in [QxMD Read])

XI. Dosing: Children with Vitamin D Deficiency (Rickets)

  1. Ergocalciferol (D2, Calciferol)
    1. Dose: 25-125 mcg (1-5000 IU) PO/IM for 6-12 weeks
  2. Cholecalciferol (D3, 40,000 IU/mg)
    1. Option 1: 125-250 mcg (5-10,000 IU) PO for 3 months
    2. Option 2: 15,000 mcg (600,000 IU) divided qid x1 day
  3. Dihydrotachysterol (DHT, 120,000 IU/mg)
    1. Option 1: 500 mcg (0.5 mg) for single dose or
    2. Option 2: 13-50 mcg PO per day until resolved
  4. References
    1. Khatib (2005) Consultant Pediatrician 4:33-9 [PubMed] (or open in [QxMD Read])

XII. Dosing: Adults with Vitamin D Deficiency

  1. Mild (Serum 25-hydroxyvitamin D 8-15 ng/ml)
    1. Vitamin D options
      1. First line
        1. Option 1: Vitamin D 50,000 IU PO weekly for 8 weeks (repeat another course if Vitamin D <30 ng/ml)
        2. Option 2: Vitamin D 1000 IU daily per every 10 ng/ml shortfall in addition to maintenance for 6 weeks
          1. Example: Vitamin D 10 ng/ml - take 2000 IU replacement in addition to 1000 IU maintenance daily
      2. Parenteral: Vitamin D 20-25 IU/kg IV daily
      3. Maintenance after acute replacement: Vitamin D 800-1000 IU PO daily
    2. Calcium 1200 to 1500 mg orally daily
  2. Severe (Serum 25-hydroxyvitamin D <8 ng/ml)
    1. Vitamin D 50,000 IU orally daily for 1-3 weeks
    2. Then maintain as mild deficiency doses above
  3. Monitoring Vitamin D level at 6-8 weeks after starting therapy
    1. Goal 25-Hydroxyvitamin D >30-40 ng/ml
    2. Storage of Vitamin D does not start until 40 ng/ml

XIII. Efficacy: Vitamin D in Osteoporosis Prevention

  1. Dutch Study of 348 women over age 70 years
    1. Given Vitamin D 400 IU or Placebo
    2. Vitamin D Group had greater BMD at 2 years
      1. Greater femoral neck Bone Mineral Density
      2. Placebo group had decreased Bone Mineral Density
    3. No change in femoral trachanter or distal radius BMD
  2. References
    1. Ooms (1995) J Clin Endocrinol Metab 80:1052-8 [PubMed] (or open in [QxMD Read])

Images: Related links to external sites (from Google)

Cost: Medications

Vitamin D (on 2/9/2012 at DrugStore.com)
Vitamin D 100 1000unit Tablets Bottle #1 for $15.99 ($15.99/unit)
Vitamin D 1000iu Tablets #100 for $15.99 ($0.16/unit)
Vitamin D (Ergocalciferol) (on 2/9/2012 at DrugStore.com)
Vitamin D (Ergocalciferol) 50000unit Capsules #100 for $100.00 ($1.00/unit)

Ontology: Cholecalciferol (C0008318)

Definition (NCI) Vitamin D synthesized from ergosterol in yeast and plants.
Definition (NCI) A nutrient that the body needs in small amounts to function and stay healthy. Cholecalciferol helps the body use calcium and phosphorus to make strong bones and teeth. It is fat-soluble (can dissolve in fats and oils) and is found in fatty fish, egg yolks, and dairy products. Skin exposed to sunshine can also make cholecalciferol. Not enough cholecalciferol can cause a bone disease called rickets. It is being studied in the prevention and treatment of some types of cancer.
Definition (CSP) produced in human and other animal tissue by photoactivation (normally sunlight on skin) of 7-dehydrocholesterol.
Definition (MSH) Derivative of 7-dehydroxycholesterol formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. It differs from ERGOCALCIFEROL in having a single bond between C22 and C23 and lacking a methyl group at C24.
Definition (NCI) A steroid hormone produced in the skin when exposed to ultraviolet light or obtained from dietary sources. The active form of cholecalciferol, 1,25-dihydroxycholecalciferol (calcitriol) plays an important role in maintaining blood calcium and phosphorus levels and mineralization of bone. The activated form of cholecalciferol binds to vitamin D receptors and modulates gene expression. This leads to an increase in serum calcium concentrations by increasing intestinal absorption of phosphorus and calcium, promoting distal renal tubular reabsorption of calcium and increasing osteoclastic resorption.
Definition (PDQ) A steroid hormone produced in the skin when exposed to ultraviolet light or obtained from dietary sources. The active form of cholecalciferol, 1,25-dihydroxycholecalciferol (calcitriol) plays an important role in maintaining blood calcium and phosphorus levels and mineralization of bone. The activated form of cholecalciferol binds to vitamin D receptors and modulates gene expression. This leads to an increase in serum calcium concentrations by increasing intestinal absorption of phosphorus and calcium, promoting distal renal tubular reabsorption of calcium and increasing osteoclastic resorption. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=39734&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=39734&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C48194" NCI Thesaurus)
Concepts Steroid (T110) , Pharmacologic Substance(T121) , Vitamin(T127)
MSH D002762
SnomedCT 18414002, 418425007, 108943009, 15211009, 126236008
English Vitamin D 3, Vitamin D3, 9,10-Secocholesta-5,7,10(19)-trien-3-ol, (3beta,5Z,7E)-, vitamin D3, (3 beta,5Z,7E)-9,10-Secocholesta-5,7,10(19)-trien-3-ol, Calciol, (3beta,5Z,7E)-9,10-Secocholesta-5,7,10(19)-trien-3-ol, Vitamin D3 (substance), Vitamin D<sub>3</sub> (substance), Vitamin D<sub>3</sub>, Colecalciferol (product), VITAMIN D A 03, 9,10-Secocholesta-5,7,10(19)-trien-3-beta-ol, Delsterol, cholecalciferol, Colecalciferol preparation, calciferol, vitamin D3 (cholecalciferol) (medication), calciferol (medication), vitamins calciferol, vitamin D3 (cholecalciferol), Vtitamin D3, Vtitamin D<sub>3</sub>, Vtitamin D>3<, 9,10-Secocholesta-5,7,10(19)-trien-3-ol, Cholecalciferol [Chemical/Ingredient], CHOLECALCIFEROL, vitamin d 3, vitamin d-3, d3 vitamin, colecalciferol, vitamin d3, D3 - Cholecalciferol, VITD - Cholecalciferol, Vitamin D>3<, Cholecalciferol preparation (product), Cholecalciferol preparation, Colecalciferol, Vitamin D>3< (substance), Cholecalciferol preparation (substance), Activated 7-dehydrocholesterol preparation (substance), Activated 7-dehydrocholesterol preparation, Activated 7-dehydrocholesterol, Activated 7-dehydrocholesterol (substance), Activated 7-dehydrocholesterol preparation (product), Cholecalciferol
Swedish Kolekalciferol
Spanish preparado con 7-dehidrocolesterol activado (producto), 7-dehidrocolesterol activado, 7-dehidrocolesterol activado (sustancia), vitamina D<sub>3</sub> (sustancia), vitamina D3, vitamina D<sub>3</sub>, vitamina D3 (sustancia), colecalciferol (producto), preparado con colecalciferol (producto), colecalciferol, preparado con 7-dehidrocolesterol activado, preparado con colecalciferol, preparado de 7-dehidrocolesterol activado (producto), preparado de 7-dehidrocolesterol activado (sustancia), preparado de 7-dehidrocolesterol activado, preparado de colecalciferol (sustancia), vitamina D>3< (sustancia), vitamina D>3<, D3 - colecalciferol, Colecalciferol, Vitamina D 3
Czech cholekalciferol
Finnish Kolekalsiferoli
Russian VITAMIN D3, KHOLEKAL'TSIFEROL, ВИТАМИН D3, ХОЛЕКАЛЬЦИФЕРОЛ
Japanese コレカルシフェロール, ビタミンD3, オレオビタミンD3
Italian Vitamina D 3, Vitamina D3, Colecalciferolo
German VITAMIN D A 03, Cholecalciferol, Vitamin D3
Croatian KOLEKALCIFEROL
Polish Cholekalcyferol, Witamina D3
French Cholécalciférol, Vitamine D3
Portuguese Colecalciferol, Vitamina D 3

Ontology: Dihydrotachysterol (C0012319)

Definition (MSH) A VITAMIN D that can be regarded as a reduction product of vitamin D2.
Concepts Steroid (T110) , Pharmacologic Substance(T121) , Vitamin(T127)
MSH D004097
SnomedCT 20237006, 126235007
English Dihydrotachysterin, Dihydrotachysterol, Tachystin, dihydrotachysterol, 9,10-Secoergosta-5,7,22-trien-3-ol, (3beta,5E,7E,10alpha,22E)-, Dihydrotachysterol 2 preparation, Dihydrotachysterol2 preparation, Dihydrotachysterol<sub>2</sub> preparation, DIHYDROTACHYSTEROL, dihydrotachysterol (medication), vitamins dihydrotachysterol, Dihydrotachysterol [Chemical/Ingredient], [VT503] DIHYDROTACHYSTEROL, 9,10-Secoergosta-5,7,22-Trien-3-ol, (3.Beta.,5E,7E,10.Alpha.,22E)-, DHT preparation, Dichysterol preparation, Dihydrotachysterol preparation, Dihydrotachysterol>2< preparation, Dihydrotachysterol (substance), Dihydrotachysterol preparation (product), Dihydrotachysterol preparation (substance)
Swedish Dihydrotakysterol
Czech dihydrotachysterol
Finnish Dihydrotakysteroli
Russian DIGIDROTAKHISTEROL, DIGIDROTAKHISTERIN, TAKHISTIN, ДИГИДРОТАХИСТЕРИН, ДИГИДРОТАХИСТЕРОЛ, ТАХИСТИН
Japanese ジヒドロタキステロール
Spanish preparado con dihidrotaquisterol (producto), preparado con dihidrotaquisterol>2<, preparado con dihidrotaquisterol<sub>2</sub>, dihidrotaquisterol (producto), preparado con dihidrotaquisterol2, preparado con dihidrotaquisterol, dihidrotaquisterol (sustancia), dihidrotaquisterol, preparado de DHT, preparado de dicisterol, preparado de dihidrotacisterol (sustancia), Dihidrotaquisterol
Italian Diidrotachisterina, Tacistina, Diidrotachisterolo
Polish Dwuhydrotachysterol, Dihydrotachysterol
French Dihydrotachystérol
German Dihydrotachysterol
Portuguese Diidrotaquisterol

Ontology: Ergocalciferol (C0014695)

Definition (NCI) Vitamin D synthesized from 7-dehydrocholesterol in the skin after exposure to UVB radiation.
Definition (NCI) A form of vitamin D that helps the body use calcium and phosphorus to make strong bones and teeth. It is fat-soluble (can dissolve in fats and oils) and is found in plants and yeast. It can be made in the body from another form of vitamin D when the body is exposed to the sun. Ergocalciferol is also made in the laboratory. It is used to prevent and to treat vitamin D deficiency. It is a type of dietary supplement.
Definition (NCI) Vitamin D2, a fat-soluble vitamin important for many biochemical processes including the absorption and metabolism of calcium and phosphorus. In vivo, ergocalciferol is formed after sun (ultraviolet) irradiation of plant-derived ergosterol, another form of vitamin D. Ergocalciferol is the form of vitamin D usually found in vitamin supplements. (NCI04)
Concepts Organic Chemical (T109) , Pharmacologic Substance(T121) , Vitamin(T127)
MSH D004872
SnomedCT 23433006, 71516007, 30178006
English D 2, Vitamin, D2, Vitamin, Vitamin D2, Vitamin D2 preparation, Vitamin D2 (substance), Vitamin D<sub>2</sub> (substance), Vitamin D<sub>2</sub> preparation, Vitamin D<sub>2</sub>, Ergocalciferol, ergocalciferol, calciferol, VITAMIN D A 02, 9,10-Secoergosta-5,7,10(19),22-tetraen-3-beta-ol, Vitamin D, ergocalciferol (medication), vitamins ergocalciferol, vitamin D2 (ergocalciferol), vitamin D2 (ergocalciferol) (medication), 5Z,7E,22E)-(3S)-9,10-seco-5,7,10(19),22-ergostatetraen-3-ol, ERGOCALCIFEROL, [VT504] ERGOCALCIFEROL, Ergocalciferol (Vit D2), vitamin d2, vitamin D2, Calciferol, Activated ergosterol preparation, Calciferol preparation, Ergocalciferol preparation, Viosterol preparation, Ergocalciferol product, Vitamin D>2< preparation, Vitamin D>2<, Ergocalciferol preparation (product), Vitamin D>2< (substance), Ergocalciferol preparation (substance), Vitamin D 2
Spanish preparado de ergocalciferol, Vitamina D 2, vitamina D2, preparado de vitamina D<sub>2</sub>, vitamina D2 (sustancia), vitamina D<sub>2</sub> (sustancia), vitamina D<sub>2</sub>, preparado de vitamina D2, preparado con calciferol, ergocalciferol (producto), preparado con ergocalciferol (producto), ergocalciferol, preparado con ergocalciferol, preparado de calciferol, preparado de ergocalciferol (producto), preparado de ergocalciferol (sustancia), preparado de ergosterol activado, preparado de viosterol, preparado de vitamina D>2<, vitamina D>2< (sustancia), vitamina D>2<
Portuguese Vitamina D 2
German Vitamin D2, VITAMIN D A 02
Croatian VITAMIN D2

Ontology: Vitamin D (C0042866)

Definition (MEDLINEPLUS)

Vitamin D helps your body absorb calcium, which your bones need to grow. 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

  • Seniors
  • Breastfed infants
  • People with dark skin
  • People with certain conditions, such as liver diseases, cystic fibrosis and Crohn’s disease
  • People who are obese or have had gastric bypass surgery

NIH: National Institutes of Health Office of Dietary Supplements

Definition (NCI) A nutrient that the body needs in small amounts to function and stay healthy. Vitamin D helps the body use calcium and phosphorus to make strong bones and teeth. It is fat-soluble (can dissolve in fats and oils) and is found in fatty fish, egg yolks, and dairy products. Skin exposed to sunshine can also make vitamin D. Not enough vitamin D can cause a bone disease called rickets. It is being studied in the prevention and treatment of some types of cancer.
Definition (MSH) A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.
Concepts Organic Chemical (T109) , Pharmacologic Substance(T121) , Vitamin(T127)
MSH D014807
SnomedCT 30178006, 11563006
English Vitamin D, vitamin D, VITAMIN D PREPARATIONS, Vitamin D preparation, NOS, Vitamin D, NOS, Oleovitamin D, A48 VITAMIN D PREPARATIONS, vitamin D (medication), [VT500] VITAMIN D, Vitamin D [Chemical/Ingredient], vitamin d preparations, d vitamin, vit d, vitamin-d, VITAMIN D, Oleovitamin D preparation, Vitamin D product, Vitamin D (substance), Vitamin D preparation (product), Vitamin D preparation, Vitamin D preparation (substance)
Swedish Vitamin D
Czech vitamin D
Finnish D-vitamiini
Russian KAL'TSIFEROL, VITAMIN D, ВИТАМИН D, КАЛЬЦИФЕРОЛ
Spanish preparado con vitamina D (producto), vitamina D (producto), preparado con vitamina D, calciferol, hormona calciotrópica, preparado de oleovitamina D, preparado de vitamina D (sustancia), vitamina D (sustancia), vitamina D, Vitamina D
Croatian VITAMIN D
Polish Kalcyferol, Witamina D
French Vitamine D
German Calciferole, Vitamin D
Italian Vitamina D
Portuguese Vitamina D