Nutrition Questions and Answers
Vital Health Zone is proud to announce Lesa Rusher, who is our resident naturopathic expert and who is available to answer questions about nutrition and health.
Lesa Rusher is a qualified naturopath with a thriving business in Canberra, Australia and has a wealth of experience treating clients on a variety of health issues. Lesa Rusher's full credentials can be found in our experts area.
Lesa Rusher will answer your nutrition-related questions.
Q: I would like to know whether silica is toxic in large doses and how high can a silica supplement be safely taken and for how long?
A: A recommended daily intake of silica (silicon) has only been established for adults aged 19-50 years with a range of 9-14mg per day. A tolerable upper limit (the maximum that can be safely taken for short periods) has also been established in a range of 20-30mg per day for adults.
You should only take silica supplements if you are deficient in this mineral and supplementation is the only option as recommended by your doctor.
If you take a look at the ingredients list on the horsetail supplements provided by various companies for hair/skin/nails, you will see that the elemental silica found in the horsetail is only one part of the horsetail herb and is not in the same level as would be found in a silica supplement. Silica makes up around 7% of the horsetail herb, so the level of silica found in horsetail supplements is generally within the upper limit.
One recent study has suggested that neither silica deficiency nor silica deficiency symptoms have been identified in humans, so check with your doctor first before supplementing with silica.
Silica supplements can product toxicity in people at doses over 100mg per day, but horsetail supplements (which are a natural source of silica) have less toxicity at higher doses than silica, but long-term use or very high doses of horsetail supplements have caused irreversible kidney damage (from excessive silica intake). Women who are pregnant or breastfeeding should not take excessive amounts of silica and neither should people with kidney or heart disease, due to the issues with kidney function. Safety of silica in doses over 50mg has not been established, so it is not advisable to take it higher than this level.
Always check with your doctor before taking any supplements, especially if you have any health conditions or are taking medications and if you want to take the supplements long term.
Please note that the information provided is for educational purposes only and is not meant to diagnose or treat medical conditions. Consult with your medical physician regarding appropriateness of using supplements in your healing process.
Enjoy better health!