Sodium, potassium and lithium are essential elements, having major biological roles as electrolytes, and although the other alkali metals are not essential, they also have various effects on the body, both beneficial and harmful.
sˈoʊdiəm, pətˈæsiəm ænd lˈɪθiəm ɑːɹ ᵻsˈɛnʃəl ˈɛlɪmənts, hˌævɪŋ mˈeɪdʒɚ bˌaɪəlˈɑːdʒɪkəl ɹˈoʊlz æz ᵻlˈɛktɹəlˌaɪts, ænd ɔːlðˈoʊ ðɪ ˈʌðɚɹ ˈælkəlˌaɪ mˈɛɾəlz ɑːɹ nˌɑːt ᵻsˈɛnʃəl, ðeɪ ˈɔːlsoʊ hæv vˈɛɹiəs ɪfˈɛkts ɔnðə bˈɑːdi, bˈoʊθ bˌɛnɪfˈɪʃəl ænd hˈɑːɹmfəl.