The Affliction Prescribed by the Torah
The Gemara in Masechet Yoma (74b) teaches us that the primary “affliction” that the Torah commands us to observe on Yom Kippur is the oppression of not eating or drinking anything the entire day. The Gemara further points out that if one eats on Erev (the day preceding) Yom Kippur, the Torah considers it as if he has fasted for two days, the Ninth and Tenth of Tishrei. Rashi explains that the Torah has commanded us to eat on the Ninth of Tishrei so that we may be able to fast on the Tenth of Tishrei, Yom Kippur. The Rosh adds that the Torah commands us to do so in order to show us how much Hashem endears the Jewish nation, for he tells them to eat and drink adequately on the Ninth in order to be able to fast well on the Tenth of Tishrei.
We see from here that the Torah does not require us to actively oppress ourselves with regards to the fast; rather, one is only required to passively oppress one’s self by abstaining from eating and drinking on Yom Kippur. However, one is not obligated to see to it that one endures the fast with much difficulty, as the Gemara in Masechet Yoma (ibid.) tells us that one should not go sit in the sun so that one becomes overheated and oppressed, for this is not what the Torah meant by “affliction.”
Taking Vitamins Before the Fast to Garner Strength
We can likewise infer that one may implement various means to make himself endure the fast more easily. The same applies to taking “Easy Fast” pills or performing various rituals which will cause the fast to be easier for one’s self before the fast and this is indeed permissible. There is room for leniency especially with regards to an individual who suffers greatly from the fast and gets headaches. Maran Rabbeinu Ovadia Yosef zt”l rules likewise in his Responsa Yabia Omer (Volume 9) where he writes that one who suffers greatly as a result of the fast of Yom Kippur may take an “Easy Fast” pill before the fast so that he does not suffer as much during the fast.
We should point out though that there are those who are historically very bad fasters and almost faint during fast days or enter a state of tremendous weakness or illness after the fast as a result of a sodium imbalance in the body. The pills, which contain vital vitamins and minerals, are known to help with these symptoms. For such people, taking such medications or supplements before the fast is actually recommended so that they do not become ill during or after the fast.
Using Tylenol or Caffeine Suppositories
Although there is room for leniency for one who suffers from the fast to take pills or other means before the fast, nevertheless, Maran Rabbeinu Ovadia Yosef zt”l writes in his Chazon Ovadia-Yamim Nora’im that one should not act leniently and use suppositories on Yom Kippur itself to help him endure the fast more easily. He quotes the words of his friend, Hagaon Harav Shlomo Zalman Auerbach zt”l who writes that a person who does so is considered “abominable with the Torah’s permission,” for although doing so is indeed permissible according to the letter of the law, it is nevertheless considered improper to use medical measures during the fast itself to decrease one’s hunger pangs contrary to the Torah’s commandment of fasting on this day.
Only if one feels that he cannot continue to fast as a result of illness or weakness may one certainly be lenient and use such a suppository even on Yom Kippur itself so as not to come to a situation where one will have to actually eat or drink on Yom Kippur.
Summary: If one suffers greatly as a result of the fast, one may take “Easy Fast” pills before the onset of Yom Kippur. During the fast itself, one should not be lenient to use suppositories which decrease one’s hunger pangs, as we have explained.
