Getting your vitamins from food, not supplements
Most people in the UK take supplements they do not need. Here is which vitamins you can get from seasonal food and which ones actually warrant a supplement.
The UK supplement market is worth over £500 million a year. Most of it is unnecessary. The majority of vitamins people spend money on are readily available in higher concentrations and better absorbed forms from seasonal British food.
Vitamin D - the one you probably do need
This is the exception. The NHS recommends that everyone in the UK takes a 10 microgram vitamin D supplement from October through March, because UK sunlight is not strong enough during these months to trigger vitamin D production in the skin. This supplement is worth taking.
Vitamin C - you almost certainly do not need to supplement
The recommended daily intake is 40mg. A single kiwi contains 60mg. A handful of blackcurrants contains 90mg. A portion of in-season strawberries contains 50mg. If you eat any fruit or vegetables at all you are almost certainly getting enough vitamin C.
Iron - food first
Iron deficiency is common but the solution is usually dietary. Dark leafy greens and legumes are rich in iron, and eating them alongside vitamin C-rich food dramatically improves absorption. Get a blood test before supplementing - too much iron is harmful.
The principle
Eat a wide variety of seasonal fruit and vegetables in a range of colours and you will cover almost all of your micronutrient needs. Use the Ripely nutrients guide as your shopping guide rather than the supplement aisle.