The Torah gives life and health to the world and to humanity. This is especially true of Shema, which contains the principles of faith and the fulfillment of the mitzvot. The Sages teach that Shema is comprised of 248 words, just as there are 248 limbs in the human body; when one recites Shema properly, each and every limb corresponds to one word and is healed by it. However, in the three paragraphs of Shema there are actually 245 words. In order to reach 248, the ĥazan repeats the last three words, “Hashem Elokeikhem emet” (“the Lord, your God, is true”), thereby completing the count to 248 (Zohar Ĥadash Ruth 95:1; see also Peninei Halakha: Prayer 15:12).
Women, who do not pray in the synagogue, do not hear the ĥazan, and therefore must practice one would when praying individually. That is, according to Ashkenazic custom, before beginning Shema she says, “Kel Melekh ne’eman” (“God, faithful King”). Even though women have 252 limbs, as the womb has two doors and two hinges (Bekhorot 45a), since all people have 248 limbs, perhaps it is most important to direct the blessings toward them, and the blessing will then continue to the limbs unique to women (Minĥat Elazar 2:28; Ha-elef Lekha Shlomo OĤ 120).
According to Sephardic custom, one praying individually should also complete the three missing words on her own and repeat “Hashem Elokeikhem emet” (Kaf Ha-ĥayim 61:15-16). Some say that according to Sephardic custom a woman should say “Kel Melekh Ne’eman” before and also repeat “Hashem Elokeikhem emet” after Shema, thereby reaching 252 words, matching the number of her limbs (She’eirit Yosef vol. 2, p. 186).