Mary King, Leicester

She should target the B vitamins, the group largely responsible for the smooth running of the nervous system, and vitamin C, which experts believe we need in much greater quantities when we are stressed than the usual RNI (Reference Nutrient Intake) of 40mg — she probably needs more like 200mg a day.

B vitamins are found in many foods but especially pork, bacon, nuts, dairy products, fortified breakfast cereals, lean meat, fish, eggs and wholegrains — so even if your daughter can’t shop regularly, other foods can work in her favour. Tinned oily fish such as salmon, sardines and mackerel (but not tinned tuna) are good, as their omega oils can block production of the enzyme that makes us feel tense when under pressure.

Fresh produce usually has the highest and best all-round levels of nutrients such as vitamin C, but if your daughter has a freezer she could buy frozen vegetables, which contain good levels. Fresh juice — PJ or Innocent or, as a cheaper alternative, freshly made juice from the supermarket — is another good source of vitamin C.

She should avoid caffeine, as it increases the adrenaline generated at times of stress; water or herbal tea would be better. Frequent small meals can help concentration. When I was studying I relied heavily on homemade soups with plenty of beans, lentils and root vegetables (an alternative would be a good ready-made soup such as Covent Garden).

High-sugar, high-glycaemic-index foods such as biscuits and sweets could make me feel wired, and patients often feel the same; better to go for slower-released carbohydrates such as oatmeal biscuits, apples, dried apricots and figs, unsalted nuts or crackers with thin slices of cheese (good to nibble on, as is yoghurt with fresh fruit). Pasta or other starchy food, such as rice or a jacket potato, will encourage her body to produce the hormone serotonin, which helps to calm us down — it's economical, too. And drinking plenty of water can help concentration: just 5 per cent dehydration (not enough to feel thirsty) can reduce your ability to concentrate by up to 20 per cent.

Do any foods help to keep skin in good condition? Mine is smooth, normal, not dry, with a few red veins and wrinkles. I am 72 but most people say I look 62. I try to eat a healthy diet and take vitamins, but I do like cakes and sweets. I also go for a facial every six weeks or so.

Doreen Greenslade, by e-mail

You’re at least halfway there — people on Channel 4’s Ten Years Younger often have to resort to cosmetic surgery to achieve the results you’re getting. But there are other things you can do. First, if you smoke, give up. You also need to try to drink 2.5 litres of water: all my patients who do so notice a huge difference in how moist and alive their skin feels. It can take some getting used to: spread it out over the day, a glass an hour of tap water, cold, or hot with lemon or fresh mint leaves and a dash of honey.

Tea is high in anti-ageing antioxidants that can help to bat away the free radicals that cause our skin to age. However, getting your water intake by drinking 2.5 litres of tea a day could aggravate your gut (because of the tannin) and give you too much caffeine, so have a couple of good cups of tea and make up the rest with water, or herbal tea such as camomile. Fruit teas have a high acid content, which has been linked to tooth decay, so watch your intake, no more than a couple of cups a day.

I’ve seen great results with aloe vera, the cactus plant that is sold as a juice, capsule (or powder, though research indicates that this form is less effective). It has been used since ancient times to help, among others things, skin complaints such as acne, psoriasis and dry skin. Follow the recommended dose, usually about 6ml-10ml a day. I feel so well — and my skin has benefited — from taking it every morning: add a little water or mix it with fresh carrot and ginger juice.

Carrots, watercress, sweet potatoes, red peppers, kale, butternut squash, apricots, mangoes and melons are all rich in beta-carotene. This converts into vitamin A, which is good for all skin complaints and wrinkles. You also glean plenty of beta-carotene from cooked vegetables — with carrots, the more you cook, the more is released, so carrot soup is one of the best. Vitamin A creams can be prescribed for problem skin, but since yours is good, just keep up your intake of these fresh foods.

The skin’s favourite antioxidant is probably vitamin C, but supplements, while popular, are a waste of money — unless you’re a smoker, in which case take 2,000mg a day. We get enough from fresh fruits and vegetables — especially blueberries, kiwi, papaya and citrus — just by eating five portions a day.

Use hemp and walnut oil on salads. They are a good way to take in anti-ageing omega fatty acids. Seeds, nuts and oily fish are other good sources of omega oils that keep skin supple. Because of concerns over toxins, the Food Standards Agency recommends that girls, and women who might one day have a child, and women who are pregnant or breastfeeding, have up to two portions of oily fish a week, while other women, men and boys can have up to four (1 portion = 140g-ish). Avocados, almonds, sun-dried tomatoes, pine nuts, sunflower seeds and Brazil nuts are rich in selenium and vitamin E, both skin-nurturing nutrients. Other good sources are wholewheat cereals such as Bran Flakes and Shredded Wheat.

It’s a myth that sweet foods cause poor skin; chocolate doesn’t cause spots. High-cocoa-bean chocolate, 70 per cent-plus, provides good antioxidants, a perfect excuse for indulging at Easter.

SEND JANE YOUR QUERIES

Send your nutritional problems to jane.clarke@thetimes.co.uk or to Jane Clarke, T2, 1 Pennington St, London E98 1TT. Jane’s replies cannot apply to individual cases and should be taken in a general context. Consult your GP if you suffer from any health or specific conditions. Jane cannot enter into personal correspondence. Visit her website: www.janeclarke.com

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