There is no daily recommended intake for silica, but its presence in our bones, tendons, and other tissues suggests it may play a beneficial role in our health. Nutrition Diva explains where you'll find it.
Q. "I recently read that bamboo is very high in silica. There is lots of bamboo around where I live and I'd like to get more of this nutrient in my diet. But what part of the bamboo plant should I eat?"
A. Unless you're a panda bear, I wouldn't recommend chewing on bamboo growing in your neighborhood. Raw bamboo shoots (which is the only edible part of the plant) contain a toxin that can make you sick. The shoots are traditionally pickled or fermented, which neutralizes the toxin and makes them edible. Recently, bamboo extracts have been touted as a source of silica. But there are easier ways to get silica from foods.
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There isn't any recommended daily intake of silica because it hasn't yet been recognized as an essential nutrient. However, its presence in our bones and other tissues suggest that it plays some sort of role in our health. It sometimes turns up in multi-vitamin formulations but I don't think there's any need to supplement with this nutrient. Eating a varied diet of whole foods should cover your bases.
Martin KR. The chemistry of silica and its potential health benefits. J Nutr Health Aging. 2007 Mar-Apr;11(2):94-7.
Powell JJ, McNaughton SA, et al. A provisional database for the silicon content of foods in the United Kingdom. Br J Nutr. 2005 Nov;94(5):804-12.