What factor can contribute to hair thinning in adults?

Hair thinning in adults can result from a combination of various factors, and the correct answer encompasses all listed options. Each of these factors plays a significant role in the health and density of hair.

A lack of essential vitamins and minerals, such as vitamin D, iron, and biotin, can hinder hair growth and lead to thinning. These nutrients are crucial for maintaining healthy hair follicles and supporting the hair growth cycle.

Hormonal changes, particularly those associated with aging, pregnancy, menopause, or health conditions such as polycystic ovary syndrome (PCOS), can significantly affect hair growth. Hormones like androgens can lead to the miniaturization of hair follicles, resulting in thinner hair.

Stress is another critical factor that can lead to hair thinning. High levels of stress can trigger a condition known as telogen effluvium, where hair follicles prematurely enter the resting phase of the hair growth cycle, leading to increased shedding and thinning.

Since all these factors can intertwine and contribute to hair thinning, recognizing them collectively provides a more comprehensive understanding of the issue. Each person's situation is unique, and multiple influences can come into play simultaneously, making it clear why all of these factors are relevant when discussing causes of hair thinning in adults.