Hi. Thanks for writing in to healthcaremagic. Its very difficult to make a confirmatory diagnosis without having visually examined a patient. However, pityriasis alba however seems to be the most likely condition we are dealing over here. Clinically, these patches are ill-defined, off-white in color and there might be some scaling as well. However I would like to rule out a possibility Pityriasis versicolor by a KOH Scraping for fungal elements. Follow up with a dermatologist with the test report or you can write in to me directly on this forum. Pityriasis alba in more common in those who have a dry skin and can become more prominent in dry weather like winters. Underlying vitamin deficiency is not implicated in its causation. I would suggest you to use a gentle cleanser, moisturize twice daily and apply a mild topical steroid e.g hydrocortisone cream, twice daily over the patches Take care regards