WARNINGS
Hypersensitivity to vitamin D may be one etiologic factor in
infants with idiopathic hypercalcemia. In these cases vitamin D must be strictly
restricted.
Keep out of the reach of children.
PRECAUTIONS
General
Vitamin D administration from fortified foods, dietary
supplements, self-administered and prescription drug sources should be
evaluated. Therapeutic dosage should be readjusted as soon as there is clinical
improvement. Dosage levels must be individualized and great care exercised to
prevent serious toxic effects. IN VITAMIN D RESISTANT RICKETS THE RANGE BETWEEN
THERAPEUTIC AND TOXIC DOSES IS NARROW. When high therapeutic doses are used
progress should be followed with frequent blood calcium determinations. In the
treatment of hypoparathyroidism, intravenous calcium, parathyroid hormone,
and/or dihydrotachysterol may be required.
Maintenance of a normal serum phosphorus level by dietary phosphate
restriction and/or administration of aluminum gels as intestinal phosphate
binders in those patients with hyperphosphatemia as frequently seen in renal
osteodystrophy is essential to prevent metastatic calcification. Adequate
dietary calcium is necessary for clinical response to vitamin D therapy.
Protect from light.
Drug Interactions
Mineral oil interferes with the absorption of fat-soluble
vitamins, including vitamin D preparations. Administration of thiazide diuretics
to hypoparathyroid patients who are concurrently being treated with
ergocalciferol capsules may cause hypercalcemia.
Carcinogenesis,
Mutagenesis, Impairment of Fertility
No long-term animal studies have been performed to evaluate the
drug's potential in these areas.
Pregnancy Category C
Animal reproduction studies have shown fetal abnormalities in several species
associated with hypervitaminosis D. These are similar to the supravalvular
aortic stenosis syndrome described in infants by Black in England (1963). This
syndrome was characterized by supravalvular aortic stenosis, elfin facies, and
mental retardation. For the protection of the fetus, therefore, the use of
vitamin D in excess of the recommended dietary allowance during normal pregnancy
should be avoided unless, in the judgment of the physician, potential benefits
in a specific, unique case outweigh the significant hazards involved. The safety
in excess of 400 USP Units of vitamin D daily during pregnancy has not been
established.
Nursing Mothers
Caution should be exercised when ergocalciferol capsules are
administered to a nursing woman. In a mother given large doses of vitamin D,
25-hydroxycholecalciferol appeared in the milk and caused hypercalcemia in her
child. Monitoring of the infant's serum calcium concentration is required in
that case (Goldberg, 1972).
Pediatric Use
Pediatric doses must be individualized (see DOSAGE AND ADMINISTRATION).
Geriatric Use
Clinical studies of ergocalciferol capsules did not include
sufficient numbers of subjects aged 65 and over to determine whether they
respond differently from younger subjects. Other reported clinical experience
has not identified differences in responses between the elderly and younger
patients. A few published reports have suggested that the absorption of orally
administered vitamin D may be attenuated in elderly compared to younger,
individuals. In general, dose selection for an elderly patient should be
cautious, usually starting at the low end of the dosing range, reflecting the
greater frequency of decreased hepatic, renal, or cardiac function, and of
concomitant disease or other drug therapy.
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