A hypertensive patient is taking supplements including Vitamins B3, B12, C, and E. An increase in which vitamin would most likely compromise this patient's health?

In a hypertensive patient, excess Vitamin E is most concerning. High-dose Vitamin E (>400 IU/day) inhibits platelet aggregation and affects coagulation, significantly increasing the risk of hemorrhagic stroke in hypertensive individuals. This is particularly significant if the patient is also on antihypertensive medications or antiplatelet agents. Additionally, high-dose Vitamin E has been associated with increased all-cause mortality in meta-analyses. Vitamin B12 excess is renally excreted (water-soluble). Vitamin C in excess is also water-soluble and largely excreted, though very high doses can cause GI upset and kidney stones. Vitamin B3 in pharmacological doses causes flushing and can affect liver function, but in a straightforward hypertension scenario, the antiplatelet and hemorrhagic risk of excess Vitamin E is the most clinically significant answer.