Natural health products, such as amino acids, herbs, vitamins and other nutritional supplements, have an extraordinarily safe usage history.
In the USA, close to half of the population takes herbal or nutritional supplements every day. That is over 145,000,000 individual doses daily, for a total of over 53 billion doses annually.

The most elementary of forensic arguments is, where are the bodies?

To try to answer this question, we may turn to the 2003 Annual Report of the American Association of Poison Control Centers Toxic Exposures Surveillance System, published in the American Journal of Emergency Medicine, Vol. 22, No. 5, September 2004.

This report states that there have been four deaths attributed to vitamin/mineral supplements in the year 2003. Two of those deaths were due to iron poisoning. That means there have been two deaths allegedly caused by vitamins, out of over 53 billion doses. That is a product safety record without equal.

Pharmaceutical drugs, on the other hand, caused over 2,000 poison control-reported deaths, including
Antibiotics: 13 deaths
Antidepressants: 274 deaths
Antihistamines: 64 deaths
Cardiovascular drugs: 162 deaths

It would be incorrect to state that only prescription drugs kill people. In 2003, there were 59 deaths from aspirin alone. That is a death rate nearly thirty times higher than that of iron supplements. Furthermore, there were still more deaths from aspirin in combination with other products.

Fatalities are by no means limited to drug products. In the USA in the year 2003, there was a death from "Cream/lotion/makeup," a death from "Granular laundry detergent," one death from "Gun bluing," one death from plain soap, one death from baking soda, and one death from table salt.

Other deaths reported by the American Association of Poison Control Centers included:

aerosol air fresheners: 2 deaths
nailpolish remover: 2 deaths
perfume/cologne/aftershave: 2 deaths
charcoal: 3 deaths
dishwashing detergent: 3 deaths
(and interestingly, weapons of mass destruction: 0 deaths)

In America in 2003, there were 28 deaths from heroin, and yet acetaminophen ("Tylenol") alone killed 147. Though acetaminophen killed over five times as many, few would say that we should make this generally-regarded-as-safe, over-the-counter pain reliever require prescription.
Even caffeine killed two people in 2003, a number equal to the two fatalities attributed to non-iron vitamin/mineral supplements. Tea, coffee and cola soft drinks are not sold with restriction, prescription, or in childproof bottles, and rather few would maintain that they need to be.