Skip to Content

Ergocalciferol

Medically reviewed on Nov 15, 2018

Pronunciation

(er goe kal SIF e role)

Index Terms

  • Activated Ergosterol
  • D2
  • Viosterol
  • Vitamin D2

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule, Oral:

Drisdol: 50,000 units [contains brilliant blue fcf (fd&c blue #1), soybean oil, tartrazine (fd&c yellow #5)]

Generic: 50,000 units

Solution, Oral:

Calcidol: 8000 units/mL (60 mL) [contains propylene glycol]

Calciferol: 8000 units/mL (60 mL) [contains propylene glycol]

Drisdol: 8000 units/mL (60 mL [DSC]) [contains propylene glycol]

Generic: 8000 units/mL (60 mL)

Tablet, Oral:

Generic: 400 units, 2000 units

Brand Names: U.S.

  • Calcidol [OTC]
  • Calciferol [OTC]
  • Drisdol
  • Drisdol [OTC] [DSC]

Pharmacologic Category

  • Vitamin D Analog

Pharmacology

Ergocalciferol (vitamin D2) is a provitamin. The active metabolite, 1,25-dihydroxyvitamin D (calcitriol), stimulates calcium and phosphate absorption from the small intestine, promotes secretion of calcium from bone to blood; promotes renal tubule phosphate resorption.

Absorption

Absorbed in the small intestine; fat soluble; requires bile (IOM 2011)

Metabolism

Inactive until hydroxylated hepatically to 25-hydroxyvitamin D [25(OH)D; calcifediol] then renally to the active metabolite 1,25-dihydroxyvitamin D (calcitriol)

Excretion

Feces (IOM 2011)

Onset of Action

10 to 24 hours; Maximum effect: ~1 month following daily doses

Half-Life Elimination

Circulating: 25(OH)D: 2 to 3 weeks; 1,25-dihydroxyvitamin D ~4 hours

Use: Labeled Indications

Dietary supplement: For use as a vitamin D supplement.

Hypoparathyroidism: Treatment of hypoparathyroidism. Note: Since parathyroid hormone (PTH) is required for the conversion of vitamin D (ergocalciferol or cholecalciferol) to the active metabolite of vitamin D (1,25-dihydroxyvitamin D), alternative vitamin D preparations not dependent on this conversion (eg, alfacalcidol, calcitriol) are recommended for routine use (Endocrine Society [Brandi 2016]).

Off Label Uses

Nutritional rickets (pediatrics)

Based on the Global Consensus Recommendations on Prevention and Management of Nutritional Rickets, ergocalciferol (or cholecalciferol) is effective and recommended for the treatment of nutritional rickets in infants, children, and adolescents.

Osteoporosis prevention

Based on the Clinician's Guide to Prevention and Treatment of Osteoporosis from the National Osteoporosis Foundation (NOF), ergocalciferol is effective and recommended for the prevention of osteoporosis.

Vitamin D insufficiency/deficiency in patients with chronic kidney disease, treatment

Based on the Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline update for the diagnosis, evaluation, prevention, and treatment of chronic kidney disease–mineral and bone disorder (CKD-MBD), vitamin D insufficiency/deficiency in patients without severe and progressive hyperparathyroidism, including chronic kidney disease stages G3 to G5 and dialysis or transplant patients, should be corrected using treatment strategies recommended for the general population, which includes repletion with ergocalciferol (or cholecalciferol) [KDIGO 2009], [KDIGO 2017]. In patients in whom serum parathyroid hormone levels are progressively rising and remain persistently elevated despite correction of modifiable factors, calcitriol or vitamin D analogs are suggested instead of ergocalciferol (or cholecalciferol) [KDOQI commentary [Uhlig 2010]].

Contraindications

Hypercalcemia; malabsorption syndrome; abnormal sensitivity to the toxic effects of vitamin D; hypervitaminosis D

Note: Although the manufacturer’s labeling lists use in malabsorption syndrome as contraindicated, when dosed appropriately, ergocalciferol may be used in these patients.

Documentation of allergenic cross-reactivity for vitamin D analogues is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.

Dosing: Adult

Note: 1 mcg = 40 units

Osteoporosis prevention (off-label use): Adults ≥50 years of age: 800 to 1,000 units/day (NOF [Cosman 2014])

Vitamin D insufficiency/deficiency treatment (off-label dose): Note: Repletion strategies may vary depending on desired target serum 25(OH)D levels as well as the clinical status of the patient. The optimal serum 25(OH)D level is controversial; the Institute of Medicine recommends a 25(OH)D level >20 ng/mL as sufficient in nearly all persons (IOM 2011), whereas others have suggested targeting a level of ~30 ng/mL to minimize the risk of fractures, particularly in patients with osteoporosis (AACE/ACE [Camacho 2016]; NOF [Cosman 2014]). However, some data suggest levels >40 ng/mL (median level in one trial: ~48 ng/mL) are associated with increased risk of falls in postmenopausal women (Sanders 2010; Smith 2017).

Therefore, some experts recommend a range of 20 to 40 ng/mL as a reasonable target in most patients (Dawson-Hughes 2018). Ergocalciferol (vitamin D2) is considered an alternative agent to the use of cholecalciferol (vitamin D3) by some experts due to limited data showing slightly higher levels of serum 25(OH)D achieved with D3, especially when higher doses or longer intervals are used (Dawson-Hughes 2018; Tripkovic 2012). The following recommendations are based primarily on expert opinion and clinical experience:

Initial dosing (according to baseline serum 25(OH)D level):

Serum 25(OH)D 20 to 30 ng/mL: Initial: Supplementation dosing: Oral: 600 to 800 units once daily; a repeat serum 25(OH)D level is not required (Dawson-Hughes 2018) or 1,000 to 2,000 units once daily; may consider a repeat serum 25(OH)D level in ~3 months to determine if the target level has been achieved (Khan 2010).

Serum 25(OH)D 10 to <20 ng/mL: Initial:

Supplementation dosing: Oral: 800 to 1,000 units once daily (Dawson-Hughes 2018) or 2,000 units once daily (Khan 2010); a repeat serum 25(OH)D level should be drawn after ~3 months. If target serum 25(OH)D level has not been achieved, may increase to 2,000 units once daily or administer therapeutic dosing of 50,000 units once weekly for 6 to 8 weeks (Dawson-Hughes 2018).

OR

Therapeutic dosing (ie, high-dose ergocalciferol): Oral: 50,000 units once weekly (or 5,000 to 7,000 units once daily) for ~8 weeks followed by decreased maintenance dosing as needed to maintain target serum 25(OH)D level (AACE/ACE [Camacho 2016]; NOF [Cosman 2014])

Serum 25(OH)D <10 ng/mL or in patients with deficiency symptoms: Initial: Therapeutic dosing (ie, high-dose ergocalciferol): Oral: 50,000 units once weekly (or 5,000 to 7,000 units once daily) for 6 to 8 weeks to achieve target serum 25(OH)D level; a repeat serum 25(OH)D level should be drawn after ~3 months to assure target serum 25(OH)D level has been met (AACE/ACE [Camacho 2016]; Dawson-Hughes 2018; NOF [Cosman 2014]).

Maintenance dosing: Maintenance dosing is highly patient specific and dependent on target 25(OH)D level and may range from 600 to 800 units/day (Dawson-Hughes 2018) to 1,000 to 2,000 units/day (AACE/ACE [Camacho 2016]); NOF [Cosman 2014]).

Special populations (eg, obese patients, patients on medications known to affect vitamin D metabolism, patients with malabsorption syndromes or gastrectomy): Higher doses or longer durations may be necessary for adequate repletion (AACE/ACE [Camacho 2016]; Dawson-Hughes 2018).

Vitamin D deficiency/insufficiency in patients with chronic kidney disease (off-label use): Oral:

Note: In patients without severe and progressive hyperparathyroidism, including chronic kidney disease (CKD) stages G3 to G5 and dialysis or transplant patients, KDIGO guidelines recommend correcting vitamin D deficiency and insufficiency with treatment strategies recommended for the general population using ergocalciferol (or cholecalciferol) while avoiding hypercalcemia. An individualized monitoring approach to direct treatment is also recommended (KDIGO 2009; KDIGO 2017). In patients in whom serum parathyroid hormone levels are progressively rising and remain persistently elevated despite correction of modifiable factors, calcitriol or vitamin D analogs are suggested instead of ergocalciferol (or cholecalciferol) (KDOQI commentary [Uhlig 2010]).

In patients with CKD stages 3 to 4, the following dosing based on 25-hydroxyvitamin D serum level (25[OH]D) has been recommended (KDOQI 2003):

Serum 25(OH)D <5 ng/mL:

50,000 units/week for 12 weeks, then 50,000 units/month for 3 months

Serum 25(OH)D 5 to 15 ng/mL:

50,000 units/week for 4 weeks, then 50,000 units/month for 5 months

Serum 25(OH)D 16 to 30 ng/mL:

50,000 units/month for 6 months

Hypoparathyroidism: Note: Active vitamin D preparations (ie, alfacalcidol, calcitriol) in conjunction with calcium supplementation are recommended therapy. Addition of ergocalciferol may be considered for supplemental therapy (Endocrine Society [Brandi 2016]).

Dosing: Pediatric

Note: 1 mcg = 40 units

Dietary Reference Intake for Vitamin D: Oral

Breastfed (fully or partially) Infants: Oral: 10 mcg/day (400 units/day) beginning in the first few days of life; continue supplementation until infant is weaned to ≥1 L/day or 1 quart/day of vitamin D-fortified formula or whole milk (after 12 months of age) (Wagner, 2008)

Nonbreastfed Infants, Older Children ingesting <1,000 mL of vitamin D-fortified formula or milk: Oral: 10 mcg/day (400 units/day) (Wagner, 2008)

Children with increased risk of vitamin D deficiency (chronic fat malabsorption, maintained on chronic antiseizure medications): Oral: Higher doses may be required; use laboratory testing (25(OH)D, parathyroid hormone [PTH], bone mineral status) to evaluate (Wagner 2008)

Vitamin D deficiency, prevention (eg, Rickets prevention) (AAP [Folsom 2017]; AAP [Wagner 2008]; Munns 2016): Oral:

Breastfed infants (fully or partially): Oral: 400 units/day beginning in the first few days of life. Continue supplementation until infant is weaned to ≥1,000 mL/day or 1 qt/day of vitamin D-fortified formula or whole milk (after 12 months of age).

Formula-fed infants ingesting <1,000 mL of vitamin D-fortified formula or milk: Oral: 400 units/day

Children and Adolescents without adequate intake: Oral: 400 to 600 units/day. Note: Children with increased risk of vitamin D deficiency (chronic fat malabsorption, maintained on chronic antiseizure medications) may require higher doses. Use laboratory testing (25(OH)D, PTH, bone mineral status) to evaluate.

Vitamin D deficiency, treatment: Note: Treatment should also include calcium and phosphorus supplementation; some patients with chronic fat malabsorption, obesity, or who are maintained on chronic antiseizure medications, glucocorticoids, HIV medications, or antifungals may require higher doses of ergocalciferol (AAP [Golden 2014]):

Infants: Oral: 2,000 units daily or 50,000 units once weekly for 6 weeks to achieve a serum 25(OH)D level >20 ng/mL, followed by a maintenance dose of 400 to 1,000 units daily. Note: For patients at high risk of fractures, a serum 25(OH)D level >30 ng/mL has been suggested (AAP [Golden 2014]).

Children and Adolescents: Oral: 2,000 units daily or 50,000 units once weekly for 6 to 8 weeks to achieve a serum 25(OH)D level >20 ng/mL, followed by a maintenance dose of 600 to 1,000 units daily. Note: For patients at high risk of fractures, a serum 25(OH)D level >30 ng/mL has been suggested (AAP [Golden 2014]).

Vitamin D insufficiency or deficiency associated with CKD (stages 2 to 5, 5D); serum 25 hydroxyvitamin D (25[OH]D) level <30 ng/mL (KDOQI 2009): Oral:

Serum 25(OH)D level 16 to 30 ng/mL: Infants, Children, and Adolescents: 2,000 units/day for 3 months or 50,000 units every month for 3 months

Serum 25(OH)D level 5 to 15 ng/mL: Infants, Children, and Adolescents: 4,000 units/day for 12 weeks or 50,000 units every other week for 12 weeks

Serum 25(OH)D level <5 ng/mL: Infants, Children, and Adolescents: 8,000 units/day for 4 weeks then 4,000 units/day for 2 months for total therapy of 3 months or 50,000 units/week for 4 weeks followed by 50,000 units 2 times monthly for a total therapy of 3 months

Maintenance dose (once repletion accomplished; serum 25(OH)D level >30 ng/mL): Infants, Children, and Adolescents: 200 to 1,000 units/day

Nutritional rickets, treatment (off-label use): Limited data available (Munns 2016): Administer in combination with calcium supplementation:

Daily therapy (preferred):

Infants: Oral: 2,000 units daily for ≥3 months, followed by maintenance dose of 400 units daily

Children: Oral: 3,000 to 6,000 units daily for ≥3 months, followed by maintenance dose of 600 units daily

Adolescents: Oral: 6,000 units daily for ≥3 months, followed by maintenance dose of 600 units daily

Single-dose therapy: Note: While ergocalciferol can be used, cholecalciferol is the preferred supplement for single-dose therapy due to longer half-life.

Infants ≥3 months: Oral: 50,000 units once, or in divided doses over several days; after 3 months, initiate maintenance dose of 400 units daily

Children: Oral: 150,000 units once, or in divided doses over several days; after 3 months, initiate maintenance dose of 600 units daily

Adolescents: Oral: 300,000 units once, or in divided doses over several days; after 3 months, initiate maintenance dose of 600 units daily

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer’s labeling.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer's labeling.

Administration

Liquid vitamin D preparations have the potential for dosing errors when administered to infants. The FDA recommends using droppers that deliver no more than 400 units per dose for products intended for infants.

Dietary Considerations

Vitamin D is found in egg yolks, fatty fish, fortified milk, fortified cereal, and infant formulas; it is also produced by exposure to sunlight (IOM 2011). Multivitamin supplements containing vitamin D may be required for breast fed infants, those ingesting <1,000 ml/day of vitamin D-fortified formula or milk, adolescents who do not obtain 400 units/day through vitamin D-fortified milk (100 units/8 ounce serving), and children at increased risk of vitamin D deficiency.

Supplemental calcium and/or phosphorous may be required depending on the indication for therapy. Alternately, a low phosphate diet and/or the use of a nonaluminum-binding agent may be required.

Dietary Reference Intake for Vitamin D (IOM 2011):

Infants 0 to 12 months: Adequate intake: 400 units/day

1 to 18 years: RDA: 600 units/day

19 to 70 years: RDA: 600 units/day

>70 years: RDA: 800 units/day

Pregnancy/Lactating: RDA: 600 units/day

Storage

Store at 15°C to 30°C (59°F to 86°F). Protect from light.

Drug Interactions

Aluminum Hydroxide: Vitamin D Analogs may increase the serum concentration of Aluminum Hydroxide. Specifically, the absorption of aluminum may be increased, leading to increased serum aluminum concentrations. Avoid combination

Bile Acid Sequestrants: May decrease the serum concentration of Vitamin D Analogs. More specifically, bile acid sequestrants may impair absorption of Vitamin D Analogs. Management: Avoid concomitant administration of vitamin D analogs and bile acid sequestrants (eg, cholestyramine). Separate administration of these agents by several hours to minimize the potential risk of interaction. Monitor plasma calcium concentrations. Consider therapy modification

Calcium Salts: May enhance the adverse/toxic effect of Vitamin D Analogs. Monitor therapy

Cardiac Glycosides: Vitamin D Analogs may enhance the arrhythmogenic effect of Cardiac Glycosides. Monitor therapy

Danazol: May enhance the hypercalcemic effect of Vitamin D Analogs. Monitor therapy

Mineral Oil: May decrease the serum concentration of Vitamin D Analogs. More specifically, mineral oil may interfere with the absorption of Vitamin D Analogs. Management: Avoid concomitant, oral administration of mineral oil and vitamin D analogs. Consider separating the administration of these agents by several hours to minimize the risk of interaction. Monitor plasma calcium concentrations. Consider therapy modification

Multivitamins/Fluoride (with ADE): May enhance the adverse/toxic effect of Vitamin D Analogs. Avoid combination

Multivitamins/Minerals (with ADEK, Folate, Iron): May enhance the adverse/toxic effect of Vitamin D Analogs. Avoid combination

Orlistat: May decrease the serum concentration of Vitamin D Analogs. More specifically, orlistat may impair absorption of Vitamin D Analogs. Management: Monitor clinical response (including serum calcium) to oral vitamin D analogs closely if used with orlistat. If this combination must be used, consider giving the vitamin D analog at least 2 hrs before or after orlistat. Consider therapy modification

Sucralfate: Vitamin D Analogs may increase the serum concentration of Sucralfate. Specifically, the absorption of aluminum from sucralfate may be increased, leading to an increase in the serum aluminum concentration. Avoid combination

Thiazide and Thiazide-Like Diuretics: May enhance the hypercalcemic effect of Vitamin D Analogs. Monitor therapy

Vitamin D Analogs: May enhance the adverse/toxic effect of other Vitamin D Analogs. Avoid combination

Adverse Reactions

Frequency not defined: Endocrine & metabolic: Hypervitaminosis D

Warnings/Precautions

Disease-related concerns:

• Hyperphosphatemia: Normal serum phosphorous concentrations must be maintained in patients treated for hyperphosphatemia to prevent metastatic calcification.

• Obesity: Adults with a BMI >30 kg/m2 are at high risk for vitamin D deficiency due to storage of vitamin D in adipose tissue. Doses higher than the RDA may be required, but must be carefully monitored to avoid toxicity.

• Renal impairment: Metabolism of vitamin D may be altered in patients with chronic kidney disease. Supplementation with ergocalciferol may be needed; close monitoring is required (KDIGO 2009).

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Dosage form specific issues:

• Propylene glycol: Oral solutions may contain propylene glycol; toxicities may occur if large doses of vitamin D are required. Alternate dosage forms/products should be used (Misra 2008).

• Tartrazine: Products may contain tartrazine, which may cause allergic reactions in certain individuals.

Other warnings/precautions:

• Appropriate use: Adequate calcium supplementation is required; calcium and phosphorous levels must be monitored during therapy. All sources of vitamin D (eg, dietary supplements, fortified foods, medication) should be evaluated.

• Toxicity: Effects of vitamin D can last ≥2 months after therapy is discontinued.

Monitoring Parameters

Signs/symptoms of vitamin D toxicity (eg, hypercalcemia, hypercalciuria, confusion, nausea/vomiting, tremor, weakness) (ASPEN [Clark 2012])

Adults:

Serum 25(OH)D: ~3 months after initiation or dosage adjustment. In healthy patients initiating supplementation dosing, routine monitoring is not required (Dawson-Hughes 2018).

Additional monitoring of calcium, phosphorous, parathyroid hormone (PTH), and alkaline phosphatase may be required depending on severity of 25(OH)D deficiency and/or concomitant clinical condition (eg, chronic kidney disorder [CKD], hypoparathyroidism) (Dawson-Hughes 2018; Endocrine Society [Brandi 2016]; KDIGO 2017).

Infants, Children, and Adolescents:

Vitamin D deficiency: Serum calcium, phosphorus, and alkaline phosphatase (ALP) one month after starting therapy; serum calcium, phosphorous, magnesium, ALP, 25(OH)D, and PTH as well as x-ray (may also consider urine calcium/creatinine ratio) after 3 months; 25(OH)D yearly (Misra 2008).

Increased risk of vitamin D deficiency (eg, chronic fat malabsorption, chronic antiseizure medication use): Serum 25(OH)D, PTH, and bone mineral status (baseline); if vitamin D supplement is required, repeat 25(OH)D levels at 3-month intervals until normal. PTH and bone mineral status should be monitored every 6 months until normal (Wagner 2008).

CKD: Measure serum 25(OH)D levels after 3 months of treatment. Measure corrected total calcium and phosphorous after 1 month and then at least every 3 months (KDOQI 2009).

Pregnancy Considerations

Adverse events were observed in some animal reproduction studies. The ergocalciferol (vitamin D2) metabolite, 25(OH)D, crosses the placenta; maternal serum concentrations correlate with fetal concentrations at birth (Misra 2008; Wagner 2008).

Vitamin D deficiency in a pregnant woman may lead to a vitamin D deficiency in the neonate (Misra 2008; Wagner 2008). Serum 25(OH)D concentrations should be measured in pregnant women considered to be at increased risk of deficiency (ACOG 2011). The amount of vitamin D contained in prenatal vitamins may not be adequate to treat a deficiency during pregnancy; although larger doses may be needed, current guidelines recommend a total of 1000 to 2000 units/day until more safety data is available (ACOG 2011). In women not at risk for deficiency, doses larger than the RDA should be avoided during pregnancy (ACOG 2011).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Hide