Can you still refrigerate and use margarine if been left out of the fridge overnight?

No, margarine should not be refrigerated and used if it has been left out of the fridge overnight.

_Butter_ can stay out at room temperature for several days, but margarine is a different product. It is made with vegetable oils, which can become rancid if left out at room temperature. Rancid margarine can cause stomach upset and other health problems.

Additionally, margarine is typically fortified with vitamins A and D. These vitamins can degrade when exposed to heat and light, so it's best to keep margarine refrigerated to maintain its nutritional value.