Dr Sarah answers your questions
Speak to mum about tantrums
When I look after my three-year-old nephew he behaves badly with tantrums. When I placate him with sweets or toys he's good for five minutes before reverting to a little horror again. Any advice on what to do?
It's difficult to chastise a child belonging to someone else. Have a word with his mum to see if she is having problems with him too.
If so, diet should always come first - encourage her to reduce his intake of additives and sweet, stodgy foods. A fish oil supplement such as Healthspan's Brain Boosters may also help to improve his behaviour and ability to concentrate (www.healthspan.co.uk, telephone 0800 73 123 77).
A reward system is also worth considering, such as the new Identikids Reward Bands. Simply fasten one around your nephew's arm and when he's good he gets to choose his own sticker as a reward for positive behaviour.
Reward Bands are available from www.identifyme.co.uk Each pack costs £5 and includes 15 wristbands and 135 stickers.
I'm in my late 30s and think I'd like to have another baby in a few years time. Are there any tests to show how much longer I will remain fertile?
More women now have babies in their 30s than in their 20s, and the number of women planning a pregnancy in their 40s is increasing, too.
A fertility monitor kit is available from Boots that gives an indication of both male and female fertility (Fertell £79.99, www.fertell.co.uk).
The female part of the test measures levels of Follicle Stimulating Hormone (FSH) in a urine sample with results ready in 30 minutes.
A more accurate measure of the number of eggs you have left is to measure blood levels of Anti-Mullerian Hormone (AMH) which is made by cells surrounding the eggs remaining in your ovaries. This helps to assess how many eggs you have left, and can be a useful tool for women deciding whether or not to postpone having a baby. This blood test (Vita+ £179) is available from www.immogenics.com (0845 833 9153).
Sports drinks explained
I perspire a lot when working out at the gym and wonder about using the sports drinks that I see on sale to replace the salt I'm using. What is their advantage?
If you are not experiencing muscle cramps after exercise, it is unlikely that you are salt deficient, as although salts are dissolved in sweat and urine, you will have lost much more water than salts overall.
The first thing to do is to drink at least a pint of plain water, before moving on to an isotonic solution.
Isotonic sports drinks contain the same concentration of salts as body fluids plus additional glucose.
These are widely available in chemists and health food stores. Most contain lots of artificial preservatives, flavours and colourings.
Taut Isotonic is a 'clean' sports drink in that it contains no E numbers - just spring water, fruit juice and natural sugars, plus selected vitamins and minerals.
Regular use of sports drinks can affect your teeth, according to a study published in the British Journal of Sports Medicine.
Isotonic drinks have a high acid and sugar content that can dissolve tooth enamel.
Drink them chilled rather than warm, and preferably with a straw.
Horsetail may help with your thinning hair worry
My hair has got thinner and my GP has given me a three-month course of Dianette. What supplements can help?
Thinning hair is sometimes linked with scalp skin conditions, lack of iron, an underactive thyroid gland or recent hormone changes (eg pregnancy) but often no obvious cause is found. Stress plays a major role and it is important to reduce stress levels.
Follow a diet that is as organic as possible and take one of the many herbal products designed to nourish hair, skin & nails which contain herbs such as Horsetail - a rich source of silica, plus vitamins and minerals important for hair health.