Frozen vegetables can have the same or sometimes more vitamins than fresh vegetables, so in other words, they don’t lose their vitamins! How?
Frozen vegetables are frozen at their freshest, which helps maintain and preserve their vitamins and minerals. On the other hand, fresh vegetables spend more time on transport and on a shelf in grocery stores, which exposes them to light and air, all of which leads to vitamin and mineral loss.
Conclusion: fresh vegetables are best consumed as soon as possible after harvesting, if you have limited availability for fresh vegetables, frozen vegetables are your best option.