Thank you for your advice about keratosis pilaris (August 23), which I have suffered from since I was a child. My two-year-old son has pimples on his face and arms. Can I do something to prevent him developing it further?

Your son does not necessarily have keratosis pilaris, and the advice I gave previously would not be appropriate for someone so young. However, foods that are rich in vitamin A would be beneficial to his skin and liver. Give him organic liver, oily fish (such as mackerel), and green and yellow fruits and vegetables. He might love, like my two-year-old, apple and carrot juice made in a juicer. Identify food intolerances: he might be sensitive to dairy, citrus fruits, additives, eggs, peanuts, tomatoes or wheat, or irritated by washing powder, fabric conditioner, dust or mites. Pour a dessertspoon a day of Udo's Oil (a blend of omega-3 and omega-6 fatty acids to nourish his skin from the inside) on foods or in drinks (Savant Distribution, 08450 606070; www.savant-health.com). Use only natural products in the bath and on his skin - Green People (01444 401444; www.greenpeople.co.uk) makes organic liquid soap and shampoo; its Baby Skin Salve is excellent for dry skin.

I have had three chest infections during the past six months, two of which resulted in me having to take time off work. During the first bout, I went to my doctor, who, reluctantly, prescribed antibiotics. In fairness to him, they provided little relief. During the second and third bouts, I let them run their course. Can you suggest any alternative treatment?

N-Acetyl-L-Cysteine, or NAC, is an amino acid precursor to glutathione - an antioxidant found in almost every cell of the body. It protects the lungs against free radical damage - which is believed to be a cause of cancer and many chronic respiratory diseases. Numerous people susceptible to chest infections swear by it; and in a recent study of 2,500 patients with severe respiratory illness, most taking NAC found a significant decrease in coughing and mucus production. NAC generally boosts the immune system: 3 x 500mg daily, taken with meals, is recommended, but not if you suffer from peptic ulcers or are taking drugs that cause gastric lesions. Vitamin C (2,000mg), vitamin E, betacarotene, zinc and immune-boosting herbs such as echinacea are also helpful.

I suffer from brown stains on my hands. They look like large, untidy freckles, and are so awful that I find myself sitting on my hands. I am 52.

The brown stains (liver spots or age spots) are a sign of free radical damage due to poor diet, excessive sun exposure, lack of exercise or poor liver function. To support the liver, take vitamins A, C and E, mineral selenium and zinc, and the herb milk thistle. Avoid caffeine, fried foods, rancid oils, tobacco, sugar and sunbathing. C-Light Skin Tone Balancer, by Jason Cosmetics, safely inhibits melanin production (skin darkening) and reduces existing epidermal hyperpigmentation. It contains free radical scavengers from super oxide dismutase liposomes, with none of the harmful ingredients often used for skin lightening. All are available from healthfood shops or The Nutri Centre (0800 587 2290; www.nutricentre.com).

· 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.