VI-DOM-A

Clinical safety rating: caution

Comprehensive clinical and safety monograph for VI-DOM-A (VI-DOM-A).

How it works

Retinol binds to retinoic acid receptors (RARs) and retinoid X receptors (RXRs), modulating gene transcription involved in cell growth, differentiation, and immune function.

What the body does with it

Metabolism	Hepatic metabolism via oxidation to retinal and retinoic acid; also glucuronidation.
Excretion	Vitamin A is primarily excreted via bile and feces as metabolites. Renal excretion accounts for less than 5% of an oral dose. Unchanged vitamin A is not significantly excreted in urine.
Half-life	The terminal elimination half-life of vitamin A is 10-12 hours for retinol, but due to hepatic storage and enterohepatic recirculation, the overall body half-life can extend to 2-3 weeks with chronic dosing.
Protein binding	Retinol is bound to retinol-binding protein (RBP) and transthyretin in the plasma. Greater than 95% bound, with free retinol less than 5%. In hypervitaminosis, binding capacity may be exceeded, increasing free retinol.
Volume of Distribution	Vd is approximately 0.5-0.8 L/kg, reflecting distribution to extravascular tissues including the liver (storage), retina, and skin. The apparent Vd increases in hypervitaminosis due to nonspecific binding.
Bioavailability	Oral bioavailability is 80-90% under normal conditions, enhanced by dietary fat and bile salts. Intramuscular bioavailability is variable and generally lower due to precipitation at injection site; not a preferred route.
Onset of Action	Oral: Therapeutic effects on night blindness may be seen within 24-48 hours; peak serum retinol levels at 4-6 hours. Intramuscular: Onset 1-2 hours, but not recommended due to erratic absorption.
Duration of Action	Duration of clinical effect after a single oral dose is approximately 1-2 days for acute deficiency symptoms, but hepatic stores can maintain normal levels for weeks to months depending on baseline status.

Classification & Brands

Dosing & administration

1 mL intramuscular injection once weekly; each mL contains 100,000 IU vitamin A (as retinyl palmitate) and 50,000 IU vitamin D (as ergocalciferol).

Dosage form	CAPSULE
Renal impairment	No specific dose adjustment recommended; use with caution in severe renal impairment due to potential accumulation of vitamin A.
Liver impairment	No specific adjustment based on Child-Pugh score; avoid in severe hepatic impairment due to risk of hepatotoxicity.
Pediatric use	Children: 0.5 mL intramuscular injection once weekly; each 0.5 mL contains 50,000 IU vitamin A and 25,000 IU vitamin D; do not exceed recommended dose.
Geriatric use	Elderly: Same as adult dose (1 mL once weekly); monitor for signs of hypervitaminosis A and D, and consider lower starting dose if renal function is reduced.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for VI-DOM-A (VI-DOM-A).

Breastfeeding	VI-DOM-A is excreted into human breast milk. The M/P ratio is 0.9. Due to potential for serious adverse reactions in nursing infants, breastfeeding is contraindicated. Alternative feeding methods are recommended.
Teratogenic Risk	VI-DOM-A is classified as FDA Pregnancy Category X. There is evidence of fetal harm in the first trimester including increased risk of central nervous system defects, cardiovascular malformations, and orofacial clefts. Use is contraindicated throughout pregnancy. Risk for all trimesters is high, with no safe window.

Warnings & precautions

■ FDA Black Box Warning

Not established. No FDA boxed warning.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to vitamin A or any component; hypervitaminosis A; severe hepatic impairment.

Clinical Precautions

Precautions

Hypervitaminosis A (toxicity) with prolonged high doses; hepatotoxicity; pseudotumor cerebri; teratogenicity; avoid in pregnancy unless treating deficiency.

Clinical Tips & Counseling

Drug interactions

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VI-DOM-A

Clinical safety rating: caution

Comprehensive clinical and safety monograph for VI-DOM-A (VI-DOM-A).

How it works

Retinol binds to retinoic acid receptors (RARs) and retinoid X receptors (RXRs), modulating gene transcription involved in cell growth, differentiation, and immune function.

What the body does with it

Metabolism	Hepatic metabolism via oxidation to retinal and retinoic acid; also glucuronidation.
Excretion	Vitamin A is primarily excreted via bile and feces as metabolites. Renal excretion accounts for less than 5% of an oral dose. Unchanged vitamin A is not significantly excreted in urine.
Half-life	The terminal elimination half-life of vitamin A is 10-12 hours for retinol, but due to hepatic storage and enterohepatic recirculation, the overall body half-life can extend to 2-3 weeks with chronic dosing.
Protein binding	Retinol is bound to retinol-binding protein (RBP) and transthyretin in the plasma. Greater than 95% bound, with free retinol less than 5%. In hypervitaminosis, binding capacity may be exceeded, increasing free retinol.
Volume of Distribution	Vd is approximately 0.5-0.8 L/kg, reflecting distribution to extravascular tissues including the liver (storage), retina, and skin. The apparent Vd increases in hypervitaminosis due to nonspecific binding.
Bioavailability	Oral bioavailability is 80-90% under normal conditions, enhanced by dietary fat and bile salts. Intramuscular bioavailability is variable and generally lower due to precipitation at injection site; not a preferred route.
Onset of Action	Oral: Therapeutic effects on night blindness may be seen within 24-48 hours; peak serum retinol levels at 4-6 hours. Intramuscular: Onset 1-2 hours, but not recommended due to erratic absorption.
Duration of Action	Duration of clinical effect after a single oral dose is approximately 1-2 days for acute deficiency symptoms, but hepatic stores can maintain normal levels for weeks to months depending on baseline status.

Classification & Brands

Dosing & administration

1 mL intramuscular injection once weekly; each mL contains 100,000 IU vitamin A (as retinyl palmitate) and 50,000 IU vitamin D (as ergocalciferol).

Dosage form	CAPSULE
Renal impairment	No specific dose adjustment recommended; use with caution in severe renal impairment due to potential accumulation of vitamin A.
Liver impairment	No specific adjustment based on Child-Pugh score; avoid in severe hepatic impairment due to risk of hepatotoxicity.
Pediatric use	Children: 0.5 mL intramuscular injection once weekly; each 0.5 mL contains 50,000 IU vitamin A and 25,000 IU vitamin D; do not exceed recommended dose.
Geriatric use	Elderly: Same as adult dose (1 mL once weekly); monitor for signs of hypervitaminosis A and D, and consider lower starting dose if renal function is reduced.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for VI-DOM-A (VI-DOM-A).

Breastfeeding	VI-DOM-A is excreted into human breast milk. The M/P ratio is 0.9. Due to potential for serious adverse reactions in nursing infants, breastfeeding is contraindicated. Alternative feeding methods are recommended.
Teratogenic Risk	VI-DOM-A is classified as FDA Pregnancy Category X. There is evidence of fetal harm in the first trimester including increased risk of central nervous system defects, cardiovascular malformations, and orofacial clefts. Use is contraindicated throughout pregnancy. Risk for all trimesters is high, with no safe window.

Warnings & precautions

■ FDA Black Box Warning

Not established. No FDA boxed warning.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to vitamin A or any component; hypervitaminosis A; severe hepatic impairment.

Clinical Precautions

Precautions

Hypervitaminosis A (toxicity) with prolonged high doses; hepatotoxicity; pseudotumor cerebri; teratogenicity; avoid in pregnancy unless treating deficiency.

Clinical Tips & Counseling

Drug interactions

Loading safety data…