By Roland Pease
BBC Science correspondent
Medical researchers and health organisations have condemned an advert promoting vitamin supplements as a safe and effective way to treat HIV/Aids.
The UN said the advert was "wrong and misleading"
The full-page advert, published in the International Herald Tribune and the New York Times, says anti-retroviral drugs are a form of genocide.
Anti-retroviral drugs are the most effective treatment for HIV/Aids.
The advertising campaign started last year in South Africa, where Aids workers were quick to condemn it.
Dr Matthias Rath has taken his argument to the international stage by placing the colour advert in two prestigious newspapers.
Headlined "Stop Aids genocide by the drug cartel", it asserts that antiretroviral drugs undermine the body's immune system, and that "micro-nutrients alone can promote the defence against Aids".
But Harvard researchers, whose work is cited in the advert, complain that Dr Rath has misrepresented their results on the effect vitamins have on the progression towards Aids.
Their study did show multivitamin supplements slowing the progress of the disease, they say, but the pills can only postpone the moment when anti-retrovirals will be needed.
Indeed, a quarter of the patients on their vitamin treatment went on to develop full-blown Aids or died during the trial period - only a marginal improvement on the one-third of those who were on placebo treatments.
A joint statement from the World Health Organization, the UN children's fund Unicef and UNAids described Dr Rath's adverts as dangerous and unhelpful.
The fear is that those in greatest need of anti-retroviral treatments will instead turn to easier, but ineffective alternatives.
Dr Rath has long advocated the health benefits of vitamins, in conditions as diverse as cancer, heart failure and osteoporosis. The profits from his vitamin marketing company go to support his health foundation.