Vitamin D supplements and prevention of cancer and cardiovascular disease (VITAL)

Design

• Trial: VITAL — randomized, placebo-controlled, 2×2 factorial (vitamin D3 vs placebo crossed with marine n-3 vs placebo)
• This publication: vitamin D3 (cholecalciferol) 2000 IU/day vs placebo
• Population: US men ≥50 y and women ≥55 y without a strong baseline indication for either agent
• Primary end points: invasive cancer (any type) and major cardiovascular events (MI, stroke, or CV death)

Primary outcomes (intention-to-treat)

• Invasive cancer: 793 (vitamin D) vs 824 (placebo); HR 0.96 (95% CI 0.88–1.06; P = 0.47)
• Major cardiovascular events: 396 vs 409; HR 0.97 (95% CI 0.85–1.12; P = 0.69)

Selected secondary / exploratory signals (read full text)

• Death from cancer (341 events): HR 0.83 (95% CI 0.67–1.02)
• Site-specific cancers (breast / prostate / colorectal) and expanded CV composites reported in abstract with CIs spanning 1 for several comparisons

Evidence hygiene

• Oral supplement trial—not a substitute for cutaneous vitamin D synthesis trials under Daily sunlight (daily-sunlight), but it is the cleanest population RCT anchor when readers ask whether high-dose daily D prevents cancer/CVD in generally healthy older US adults.
• Pair with the companion marine n-3 VITAL publication (vital-2019-marine-n3-cancer-cvd-nejm) and Holick-style physiology reviews rather than merging slugs.

Publication

Manson JE, Cook NR, Lee IM, et al. N Engl J Med. 2019 Jan 3;380(1):33-44. PMID 30415629; NCT01169259.