It is fine to delay. This is a disease that causes problems over decades. A delay of months, or even a year, is not likely going to cause any harm. You have likely had this growing for several years already before being diagnosed (this is true for most patients), so a little longer won’t significantly harm you.

While you are waiting for the operation, the best things to do are: stay hydrated, and do not take Vitamin D or calcium supplements. If you get dehydrated, your calcium level can rise. Also, you want to avoid calcium or Vitamin D supplements. Vitamin D deficiency is common in primary hyperparathyroidism, but it does not need to be treated – it is a symptom, not the cause. Vitamin D helps your intestines absorb calcium, so taking it can raise your calcium level. Sometimes doctors will see the low Vitamin D and immediately tell you to start supplements. If you have primary hyperparathyroidism, you should avoid Vitamin D supplements. (Other vitamins and supplements are fine.)

In most cases, no medications are needed while you wait for surgery. There are medications that can lower the PTH or calcium, but these have side effects and really should not be used for primary hyperparathyroidism unless the calcium is so high that the patient is repeatedly hospitalized for it (for example, calcium levels over 15).