Possible Interaction: Vitamin A and Calcium Supplement

“This case suggests that in a setting of primary hyperparathyroidism and hydrochlorothiazide therapy, vitamin A may contribute to the development of severe hypercalcemia in patients who are on calcium and vitamin D supplements.”

“Of the 19 micronutrients investigated, the mean daily intake of eight calcium , iron, zinc, vitamin A , riboflavin, nicotinic acid, pantothenic acid and biotin) fell below the recommended dietary allowance (RDA) at both interceptions.”

“Furthermore, pharmacological preparations of fish oil contain small amounts of vitamin D but large amounts of vitamin A, which antagonises many actions of vitamin D. For example, vitamin A reduces vitamin Dinduced absorption of dietary Ca.”

“According to the experimental data, it is speculated that vitamin A may modulate the influx of calcium ion to influence the LTP and lead to the change of learning and memory.”

“3 g Ca was inhibited by retinoids ( all‐trans retinal ) and by polyunsaturated fatty acids (PUFAs) such as arachidonic acid and docosahexaenoic acid, which are known to be released in the retina by exposure to light.”

“The calcium , phosphate, magnesium, and hydroxyproline content was reduced in the vitamin A offspring.”

“The leading role in the maintenance of calcium and phosphorus homeostasis has been found to belong to vitamin D. It has been shown, however, that retinol , thiamine, riboflavine and pyridoxine as well as polyvitamin deficiencies are capable of producing an adverse effect on the calcium and phosphorus balance.”

“Addition of calcium ions to suspensions of microvillus membranes increases the fluorescence polarization of retinol and anthroyl-stearate, but not that of diphenyl-hexatriene.”

“Fortification with calcium and ascorbic acid increased liver storage of vitamin A and decreased liver:body weight ratios.”

“This effect of vit A was diminished when tissues were simultaneously stimulated with low Ca and, furthermore, absent when tissues were pre-incubated in low Ca.”