Hypervitaminosis D associated with drinking milk.

BACKGROUND: Vitamin D has been added to milk in the United States since the 1930s to prevent rickets. We report the unusual occurrence of eight cases of vitamin D intoxication that appear to have been caused by excessive vitamin D fortification of dairy milk. METHODS: Medical records were reviewed and a dietary questionnaire was sent to eight patients who had unexplained hypervitaminosis D. Vitamin D analyses with high-performance liquid chromatography were performed on samples of the patients' serum, the dairy milk they drank, and the vitamin D concentrate added to the milk. RESULTS: All eight patients drank milk produced by a local dairy in amounts ranging from 1/2 to 3 cups (118 to 710 ml) daily. All had elevated serum 25-hydroxyvitamin D concentrations (mean [+/- SD], 731 +/- 434 nmol per liter [293 +/- 174 ng per milliliter]). Six of the eight patients had elevated serum vitamin D3 concentrations. Of the eight patients, seven had hypercalcemia and one had hypercalciuria but normocalcemia (mean serum calcium, 3.14 +/- 0.51 mmol per liter [12.6 +/- 2.1 mg per deciliter]). Analysis of the dairy's vitamin D-fortified milk revealed concentrations of vitamin D3 (cholecalciferol) that ranged from undetectable to as high as 232,565 IU per quart (245,840 IU per liter). An analysis of the concentrate that was used to fortify the milk, labeled as containing vitamin D2 (ergocalciferol), revealed that it contained vitamin D3. CONCLUSIONS: Hypervitaminosis D may result from drinking milk that is incorrectly and excessively fortified with vitamin D. Milk that is fortified with vitamin D must be carefully monitored.

Hydrocortisone modulates RA-induced growth inhibition of normal and transformed human embryonic lung fibroblasts.

All-trans retinoic acid (10(-5) M) added at seeding reduces the growth rate and saturation density of normal human embryonic lung fibroblasts of two lines (WI-38 and IMR-90) and similarly inhibits growth of SV40-transformed WI-38 cells (VA13A). The growth inhibitory effects of retinoic acid do not show serum dependency, and the viability of treated cells is 95-99% of controls. Old populations of WI-38 cells (cells at high population doubling levels) are more sensitive to the effects of retinoic acid than are young populations (cells at low population doubling levels), and population life span is reduced by continuous exposure to retinoic acid. When retinoic acid is combined with the glucocorticoid hydrocortisone, inhibition of VA13A cell growth is increased, whereas the retinoic acid-induced inhibition of normal cells is decreased. VA13A cells treated with retinoic acid alone, or in combination with hydrocortisone, exhibit a reversion to a more elongated, fibroblast-like appearance. This paper discusses the clinical implications of the relationship between retinoic acid and hydrocortisone.