Mardian Natural Medicine
Vitamin K may antagonize the effect of some anticoagulant medications, and concurrent use should be medically supervised. When taken with a thiazide medication (diuretic), vitamin D may increase the risk for hypercalcemia. Also, vitamin D may improve insulin sensitivity and lower blood pressure, requiring a reduction in dosage of hypertension and/or diabetic medications. Vitamin A should not be taken with other synthetic retinoids, such as acitretin or bexarotene.