Hi Sam,
It would depend on the goods sold. Some goods are classed as exempt and sometimes the sale is simply not taxable and excluded from VAT. I would not be able to provide a list of which are which as this is very comprehensive I'm afraid. To put that in a little more perspective VAT on purchases incurred that relate to the supply of exempt supplies, in general, are not reclaimable. This is known as exempt input tax. However, provided the amount of exempt input tax is below a certain amount, it can be recovered in full. In contrast, where you sell or otherwise supply zero-rated goods or services - here you can reclaim the VAT on any purchases that relate to those sales. I would advise perhaps speaking to an accountant to understand this in the context of your situation a little bit better.
All the best,
Mohamed.