Dr. Vanita Rattan discusses five common deficiencies and hormonal reasons contributing to hairline thinning, particularly for individuals with skin of color. She emphasizes that hair loss can stem from internal factors rather than just external styling and advises seeking medical evaluation for underlying issues. The video covers vitamin D, iron/ferritin, hormonal imbalances (estrogen, thyroid, PCOS), micronutrient gaps (zinc, copper, biotin, B vitamins), and collagen/amino acid decline, offering dietary and supplementation solutions. Additionally, it touches on stress management and topical treatments like microneedling.