Vitamin makers and retailers such as Pfizer's consumer health-care unit and GNC Holdings Inc. in the U.S. and Reckitt Benckiser Group Plc and Holland & Barrett Holding Ltd. in Europe stand to benefit. The Nutrition Business Journal estimates the global market for vitamins, minerals and supplements was $30 billion in 2012 and forecasts sales will grow 3.6 percent by 2017.

In the PNAS study, researchers tracked 156 people ages 70 and older who had mild memory loss and high levels of a protein previously linked to dementia. Among people with elevated homocysteine, the study found that the amount of gray matter declined 5.2 percent in those taking a placebo, compared with 0.6 percent in those who took the vitamin cocktail. The supplements cost about 30 cents a day in pharmacies and health- food stores.

Eoin Treacy's view As incomes improve the desire to lead a healthier life that can keep the cost of personal medical care down and extend one's life expectancy is a compelling argument for considering supplements. Additionally, in countries where GP coverage is spotty, the tendency to self-medicate also helps drive demand for herbal remedies, vitamins and supplements. If supplements are seen to be of benefit to Alzheimer patients that would be a considerable bonus for a sector already benefitting from significant demand growth.

US listed GNC Holdings rallied consistently following its IPO before spending a year ranging mostly between $30 and $42. It broke upwards in April and a sustained move below $40 would be required to question medium-term scope for continued higher to lateral ranging.

Mead Johnson Nutrition found support in October near $60 and has held a progression of higher reaction lows since. A sustained move below $70 would be required to question medium-term scope for continued higher to lateral ranging.

Herbalife more than halved following a bear raid last year but rallied to break the progression of lower rally highs this week. A sustained move below $43 would be required to question recovery potential.

Dutch listed DSM NV is a globally diversified chemicals company. Nutrition is its largest unit at 40% of revenue in 2012. The share has paused in the region of €50 over the last month following an impressive advance and a sustained move below the 200-day MA, currently near €45, would be required to question medium-term scope for additional upside

UK listed Croda International is a supplier of ingredients for the dietary supplements, surfactants and plastics industries. The share found support last week in the region of the 200-day MA and a sustained move below 2450p would be required to question the consistency of the medium-term uptrend.

Mrs Treacy is a fan of Beijing Tong Ren Tang's products but apart from that I do not have a great deal of information on the company. The Hong Kong listing accelerated higher from October and posted a large downside weekly reversal in late April. A process of mean reversion is underway and a break in the short-term progression of lower rally highs will be required to check potential for additional weakness. (Also see David's piece in Comment of the Day on May 2nd).