Table 2. Protocol-Specified Adverse Events.

Event	Vitamin D (N = 1211)			Placebo (N =1212)			Incidence Rate Ratio for Vitamin D vs. Placebo (95% Cl)
	No. of Events	Event Rate	Participants with ≥1 Event	No. of Events	Event Rate	Participants with ≥1 Event
		no./100 person-yr	no.		no./100 person-yr	no.
Any adverse event leading to discontinuation of the trial pills	47	1.51		37	1.22		1.23 (0.80–1.90)
Within-trial laboratory evaluation*
Hypercalcemia	5	0.16	5	3	0.10	3	1.62 (0.39–6.77)
Fasting urine calcium:creatinine ratio >0.375	1	0.03	1	1	0.03	1	0.97 (0.06–15.52)
Low estimated glomerular filtration rate	1	0.03	1	2	0.07	2	0.48 (0.04–5.36)
Nephrolithiasis, participant-reported	25	0.80	24	21	0.69	20	1.16 (0.65–2.07)
Serious adverse event	235	7.53	173	228	7.52	153	1.00 (0.83–1.20)
Death	5	0.16		5	0.17		0.97 (0.28–3.35)

^*Hypercalcemia was defined as a serum calcium level (uncorrected for albumin level) higher than the upper limit of the normal range for the clinical laboratory at each clinical site. The fasting morning urine calcium:creatinine ratio was measured by the central laboratory. A low estimated glomerular filtration rate was defined as a rate equal to or lower than 30 ml per minute per 1.73 m² of body-surface area based on serum creatinine measured at the clinical laboratory at each clinical site.