Detailed answer

Sallow skin can be a symptom of vitamin D deficiency. Vitamin D plays a crucial role in skin health and its deficiency can lead to various skin issues, including sallow or pale skin. When the body lacks vitamin D, it can impact the production of melanin, the pigment responsible for giving skin its color. This can result in a dull, yellowish complexion. However, it's important to note that sallowness can also be caused by other factors, so it's recommended to consult a healthcare professional for an accurate diagnosis.