Conditions: Cognitive Decline
Allocation: RANDOMIZED | Intervention model: FACTORIAL
Enrollment: 3424
Healthy volunteers: yes

Brief summary:
The VITamin D and OmegA-3 TriaL (VITAL; NCT 01169259) is an ongoing randomized clinical trial in 25,875 U.S. men and women investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or omega-3 fatty acids (Omacor® fish oil, 1 gram) reduces the risk of developing cancer, heart disease, and stroke in people who do not have a prior history of these illnesses. This ancillary study is being conducted among participants in VITAL and will examine whether vitamin D or fish oil is associated with cognitive decline in 3000 older participants of VITAL.

Detailed description:
Primary aim of annual rate of cognitive decline. Secondary aims will be addressed in sub-set of participants: 1) among participants, African-American race (African-Americans have high risk of Vitamin D deficiency) modifies effects of vitamin D3 supplementation on cognitive decline; 2) among a subset of participants, baseline plasma levels of vitamin D and omega-3 fatty acids modify agent effects.

Arms:
arm 1: ACTIVE Vitamin D = Vitamin D3, one 2000 IU capsule/day; ACTIVE Omega-3 Fatty Acids = Omacor, one 1-gram capsule/day. Each capsule of Omacor contains 840 milligrams of marine omega-3 fatty acids (465 mg of eicosapentaenoic acid \[EPA\] and 375 mg of docosahexaenoic acid \[DHA\]). arm 2: ACTIVE Vitamin D = Vitamin D3, one 2000 IU capsule/day; PLACEBO Omega-3 Fatty Acids, one capsule/day arm 3: PLACEBO Vitamin D, one capsule/day; ACTIVE Omega-3 Fatty Acids = Omacor, one 1-gram capsule/day. Each capsule of Omacor contains 840 milligrams of marine omega-3 fatty acids (465 mg of eicosapentaenoic acid \[EPA\] and 375 mg of docosahexaenoic acid \[DHA\]). arm 4: PLACEBO Vitamin D, one capsule/day; PLACEBO Omega-3 Fatty Acids, one capsule/day

Interventions: intervention 1: vitamin D3 intervention 2: omega-3 fatty acids (fish oil) intervention 3: Vitamin D3 placebo intervention 4: Fish oil placebo
Intervention descriptions: intervention 1: Vitamin D3 (cholecalciferol), 2000 IU per day intervention 2: Omacor, 1 capsule per day. Each capsule of Omacor contains 840 milligrams of marine omega-3 fatty acids (465 mg of eicosapentaenoic acid \[EPA\] and 375 mg of docosahexaenoic acid \[DHA\]). intervention 3: Vitamin D placebo intervention 4: Fish oil placebo

Protocol document: