Vitamin D deficiency and itchy skin

Itch can arise from dry skin, eczema, contact irritation, insect bites, infection, hives or a medicine reaction. Sometimes the skin looks normal even when the itch is caused by a nerve, liver, kidney, thyroid or blood problem. Vitamin D may be checked when there are other reasons to suspect deficiency, but a low result does not establish that it caused the itch.

Look for clues such as a new soap, detergent, cosmetic, medicine, travel exposure, rash pattern or symptoms elsewhere. Fatigue, low mood and generalised weakness can accompany many conditions and do not identify the source of itching.

Use a plain fragrance-free moisturiser regularly, keep showers lukewarm and brief, and choose loose breathable clothing. Avoid scratching when possible; trimmed nails and a cool compress can reduce skin damage. Arrange a clinical review if itch lasts, spreads, disrupts sleep, or follows a new medicine. Do not take high-dose vitamin D or apply steroid creams widely without advice.

Seek emergency help for itch with swelling of the lips or tongue, breathing difficulty, faintness, or a rapidly spreading blistering rash. Prompt medical review is needed for yellow skin, dark urine, severe night itch, fever, pus, painful redness, or unexplained weight loss.

Ask whether the skin needs examination, which medicines or products could be responsible, and whether blood tests for thyroid, liver, kidney or nutrient problems are appropriate. Ask how to treat the itch while the cause is being investigated.