Ask most nutritionists about supplements for performance, health or any other reason and the stock answer is that a healthy diet requires no supplementation.

I'm not a nutritionist, but I have seen what works and I tend to back this view. I encourage the club cricketers I help to eat a wide range of whole food, 10 portions of fruit and vegetables a day, lean protein and healthy fats. It's a proven method.

Eating in this way will give you the minimum of every vitamin and nutrient you need to reduce the risk of disease and poor performance.

You may also know that I have supported the use of certain well proven supplements to boost performance, health or both. In short, the stuff you can't get from diet that can actually make a difference.

You could call it the difference between minimum and optimum.

Recently I have a new addition to that list: Vitamin D.

There seem to have been a range of studies all done at once on this cheap little pill. All of which are coming up with some remarkable results. Taking an excess of vitamin D has been shown to:

• Improve athletic performance
• Improve immune system performance
• Improve body composition (less fat, more muscle)
• Help prevent cancer, heart disease, diabetes and migraines
• Strengthen teeth and bones
• Boost your mood

So I recently started taking 2,000ui a day myself to try it out. I want to be optimum, not minimum.

Why does taking vitamin D work?

Vitamin D is an essential hormone in our body. We are able to produce large amounts naturally by exposure to the sun. You can also find small amounts in fish and eggs.

Because it affects over 200 genes, maintains calcium levels and is relied upon by muscle cells, not having enough can cause some serious issues in both health and performance.

In theory, nobody should have a deficiency in it because just standing out in the sun is enough to give you what you need.

Modern living is stopping us getting enough sun, even if we live in sunnier climbs:

• We spend more leisure time indoors, especially in winter
• We apply sunscreen that blocks 95% of vitamin D uptake

If, for example, you live in the UK you can almost be certain to be lacking in vitamin D in the winter months. If you are lucky enough to live somewhere sunny all year round you may still need to supplement. A recent study of women living in baking hot Texas were mostly lacking in vitamin D despite the weather.

So supplementing with Vitamin D works because it prevents the deficit that modern living gives us.

You should make sure you get enough, be it through increased exposure to sunlight (UV lamps and sunbeds or real sun in hotter countries) or taking 1-2,000ui a day in pill form.

Try it for 30 days and see if you notice a difference. Either way, let me know how it goes.

Image credit: slipstreamJC