Can taking supplements with nutrient amounts greater than the RDA be dangerous?
Toxicities of vitamins and minerals have been researched at length, and USANA has considered all available information when formulating products. Most vitamins have low toxicities, and for many no toxicity has ever been observed. Some fat-soluble vitamins can be toxic at high doses, but even when typical dietary intakes are considered, the amounts of vitamins and minerals in USANA supplements – when used as directed – do not come close to harmful levels.
Chronic intakes of vitamins and minerals at levels exceeding the LOAEL (Lowest Observed Adverse Effect Level) can cause health problems, but the amounts of vitamins and minerals found in USANA’s products have been formulated to remain below these levels. USANA products are designed to enhance health, not be detrimental to it.
A good source of information on general vitamin and mineral safety is “Vitamin and Mineral Safety, 3rd Edition” by John N. Hathcock, Ph.D. Council of Responsible Nutrition. 2014. Concerned individuals can also contact the Council for Responsible Nutrition
Additional information on this topic can be found at the following “Ask the Scientists” article: Why do I need nutritional supplements?