Table 2.
Placebo-controlled trials of vitamins & supplements in AD treatment
| Vitamin A | No randomized trials of vitamin A alone; combination studies did not use it in significant quantities. |
| B vitamins and folate | Negative [52] 2008 Multicenter trial with 340 probable AD patients (mild to mod) also taking AChEI +/− Memantine receiving neutriceutical formula (Vitamin B6 + Vitamin B12 + Folic Acid) for 18 months. Treatment group had no benefit on cognitive or functional outcomes. |
| Negative [53] 2007 Single center trial of 89 AD patients also taking AChEI received placebo or formula (B12 + B6 + folic acid + small amounts of other vitamins + iron) over 6 mos. Treatment group had no benefit on cognitive or functional outcomes. | |
| Vitamin C | Negative [54] 2012 Multicenter Phase 1 of formula containing 500 mg VitC (below). No randomized trials of vitamin C alone. |
| Negative [55] 2010 Single center trial of 23 patients with AD getting either both vitamins C and E or placebo, showed no benefit on cognition. | |
| Vitamin D | Negative [56] 2011 Single-center trial of 95 patients with AD involving both vitamin D and intranasal insulin showed no benefit of high-dose vitamin D. |
| Vitamin E | Positive [57] 1997 Multicenter Phase 3 in probable AD (moderate) for 2 yrs, showed, after adjustment, some functional, but no cognitive benefit. |
| Negative [58] 2009 Single center RCT of 57 probable AD patients also taking AChEI showed no benefit | |
| Negative [54] 2012 Multicenter RCT of formula containing 800 IU/d α-tocopherol showed some additional cognitive decline on formula. | |
| Negative [55] 2010 Single center trial of 23 patients with AD getting either both vitamins C and E or placebo, showed no benefit on cognition. | |
| Coenzyme Q | Negative [54] 2012 multicenter trial of probable AD required to be taking AChEI +/− Memantine, with duration 16 weeks. Subjects received neutriceutical formula (Vitamin E + Vitamin C + α-Lipoic acid) or Coenzyme Q. There was no benefit to cognition or function of neutriceutical or Coenzyme Q, but some evidence of worsening cognition on formula. |
| Fish-Oil/Omega-3/eicosopentonic acid (EPA) | Negative [59] 2010 Multicenter trial of 402 probable AD pts on AchEI +/− memantine showed no benefit over 18 months on cognition, function, or brain atrophy. |
| Negative [60] 2006 single center efficacy trial of 204 AD patients taking AChEI showed no benefit of DHA + EPA over 6 months on cognition. | |
| Huperzine A | Negative [61] 2011 multicenter RCT with 210 AD patients showed no effect over 16 weeks on cognition or global function |
| Gingko biloba | Negative [62] 2005 Multicenter US RCT with no benefit. |
| Negative [33] 2008 Multicenter UK RCT with no benefit. | |
| Curcurmin/Turmeric | Negative [63] 2008 Single center RCT with no benefit |
| Negative [35] 2008 Single center RCT with 36 AD patients over 48 weeks with no benefit. | |
| AC-1202/medium chain triglycerides | Negative [64] 2009 Multicenter trial did not show benefit in cognition on intent-to-treat analysis at end of trial (90 days). |
AChEI acetylcholinesterase inhibitor; RCT randomized controlled trial.