Which of the following is NOT typically a cause of hirsutism?

Dietary deficiencies are not typically recognized as a direct cause of hirsutism. Hirsutism, which is characterized by excess hair growth in women in areas where men usually grow hair, is primarily influenced by hormonal imbalances or sensitivities. Conditions such as polycystic ovarian syndrome (PCOS) are well-known for causing elevated androgen levels, leading to hirsutism. Similarly, increased cortisol levels, whether due to conditions like Cushing's syndrome or specific medications, can also result in hirsutism due to their influence on hormone regulation and metabolism.

Medication side effects frequently include hormonal changes that can contribute to excessive hair growth, positioning them as common triggers for hirsutism. In contrast, while dietary deficiencies can lead to various health issues, they aren't directly linked to the hormonal imbalances or excess androgens that usually cause hirsutism. Thus, dietary deficiencies do not fit as a typical cause of hirsutism compared to the other factors listed.