Pantothenic acid is not known to be toxic in humans. Excesses are mostly excreted in the urine (20). The only adverse effects noted were diarrhea (gastrointestinal distress) and transient nausea resulting from very high intakes (≤10–20 g/day) pantothenic acid derivates (17, 22). There is one case report of an ‘eosinophilic pleuropericardial effusion’ in an elderly woman who took a combination of 10 mg/day vitamin B7 (biotin) and 300 mg/day pantothenic acid for two months (18).
High doses of vitamin B5 can compete with biotin for the uptake by the sodium-dependent multivitamin transporter in humans (16, 23).
An increased requirement of pantothenic acid may arise when birth control pills (estrogen and progestin) are taken (17). The use of pantethine together with statins or nicotinic acid (niacin) may lead to additive effects on blood lipids (19).
Because of the potential for interactions, dietary supplements should not be taken with medication without first talking to an experienced healthcare provider.
Authored by Dr Peter Engel in 2010, reviewed and revised by Ines Warnke on 29.05.2017