Q: I always take my vitamin supplement with my morning tea. But now I hear that tea can keep some vitamins from being absorbed. Is this true? Maggie, 40

Black tea can prevent the absorption of iron, which is a big issue for many women. Generally speaking, caffeine isn’t good for the balance of your stomach acid, making it harder to absorb important minerals such as iron and calcium, as well as vitamin B12, lack of which reduces iron absorption too. Don’t switch to coffee, though, because that also blocks iron, magnesium and potassium. Consider a good-quality green tea if you need something to charge you up first thing, or a more soothing herbal tea such as lemon balm if your mornings could do with a dose of calm. If you think your stomach has already suffered from an overdose of caffeine, go for a cleansing tea such as A Vogel Golden Rod and Knotgrass (£4.59, avogel.co.uk).