Are mega-doses of vitamins safe?

Generally, no. Continuous mega-doses of vitamins or minerals can cause short and long-term adverse events. Mega-dosing vitamins refers to the practice of ingesting very large quantities (many times greater than established daily requirements) of vitamins daily with the goal of improving health, longevity or treating a condition or disease state. At high doses, many vitamins (and some minerals) function as drugs, meaning only a qualified physician might recommend high doses as a temporary therapy for a specific condition such as large doses of niacin (vitamin B3) for helping reduce cholesterol. But at these doses, the vitamin works like a drug and as with all drugs, for every action there is a reaction so a doctor must be monitoring. Below is a table that gives you a range you should stay within when trying to achieve optimal daily amounts of vitamins and minerals. Stay away from mega-dosing anything without qualified professional guidance. Upper Limit (UL) denotes the highest level of daily intake that would likely pose no risks of adverse health but unnecessary in most cases.

Chronic ingestion of nutrients anywhere in the range illustrated in Table 1 has been established as safe for the general population and may prove to be beneficial.

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