The answer is you may be able to.
The body's cells can heal by providing plenty of rest and nutrients to regenerate and repair. The average natural recovery process of a "broken" cell can be between 4 - 8 weeks. Therefore, you may be able to re-introduce that food item that you once could not tolerate.
If you want to check you have healed your intolerance, you can try a self-elimination diet that includes introducing each item one by one and waiting for a reaction which can take 3 - 5 days to surface. If you do not feel or see an unwanted symptom, it can be safe to assume you have healed that intolerance. Some clients opt for a retest after eight weeks to speed up uncovering any healed intolerances.
Please note: You may not introduce an allergic food item again; you would need to contact your medical professional or allergy specialist regarding allergies. We do not test for allergies; allergies are an immune system response and are identified only via blood. We do not require a blood sample as part of our testing methodology and therefore we can not diagnose allergies.