Impact of MA contributions less than allowed credit

I am over 65, my medical contributions are less than 3 times the tax credit. Does this negative value get carried forward and offset against any allowed medical deductions or is it zeroed?

Unfortunately if the excess of the contributions are less than 3x the credit then this part of the calculation is ignored and not taken into account.

This does not completely answer my question. If the calculation is done as per SARS example there will be a negative value. Is this then carried forward to the calculation of out of pocket expenses deduction, in effect reducing that deduction?

No, there can never be a negative value when it comes to medical aid credits and therefore if there is no amount greater than the 3x credits it gets ignored for purposes of out of pocket expenses deduction. The credit from contributions will need to be more than the 3x excess credits to carry over.