Dietary supplements refer to any health products that can supplement our diet.
They include vitamins, minerals, amino acids, digestive enzymes, probiotics, herbal supplements, glandular extracts, and dietary fibers, etc.
Some of these herbs have been used by herbalists for hundreds of years and are considered as safe.
However, when the active substances in these herbs are extracted in pure or concentrated form and consumed over prolonged period, they can be dangerous to some people.
In local news, a woman was reported to give her two teenage daughters mega dose of vitamin A for a prolonged period, thinking that the supplement is good for the eyes.
Most of the non-Spirulina blue green algae supplements are contaminated by microcystins, especially those harvested from natural lakes.