For the past few years, I've had dry, flaky fingernails and ridged thumbnails. I have a healthy lifestyle and diet. Any suggestions?

Nail problems are a sign of nutritional deficiency due to poor diet or digestive problems, such as lack of stomach acid or digestive enzymes, which prevent you from absorbing what you need from your food. Dry, brittle nails signify mineral deficiency, particularly calcium, magnesium and silica, and vitamin A. Ridges show a lack of B vitamins; if there are white spots, you may be low in zinc. Nails also need protein, iron, sulphur and essential fatty acids - evening primrose oil can be rubbed into the nails and cuticles. Since your diet is good, you should see a nutritionist to identify any digestive problems causing poor absorption (the Institute for Optimum Nutrition, 020-8877 9993).

A friend in Bulgaria gave me some 'Japanese crystals'. (I've also heard them called 'Chinese rice' and 'Caucasian salts'.) Diluted in water, they have given me so much energy, and seem to have cured my back ache and joint pain. I feel so much less frustrated and irritable. What are they, and where can I get them?

They sound like what is marketed in the UK as Himalayan crystal salt. It is claimed to be unpolluted and much better for you than sodium chloride 'table salt' (from G Baldwin & Co, 020-7703 5550; or visit bestcare-uk.com). It is likely that your mineral and trace element levels have been low for some time, which could explain your aches, pains and irritability, and these salts have replenished your reserves, making you feel altogether much healthier.

· Emma Mitchell is a natural health therapist. Before following Emma's recommendations, you should consult your GP about any medical problems or special health conditions.

Send your questions to Wellbeing, Guardian Weekend, 119 Farringdon Road, London EC1R 3ER. Email: ask.emma@theguardian.com.