Unpopular opinion, you should only give blood if it doesn't affect your health.

I have seen quite a few comments from people who are low in this or that, and wants to take supplements so they can donate again. This is not good for your health. You should only donate if all your readings are normal, and not just slightly above the limit.

Its great that you want to help others, but it shouldn't come at the expense of your own health. From what I have read, most people should not be donating more than twice a year (470ml donation) , which is the time for iron levels to recover.

To increase donations, the onus should be on getting more people to donate, not getting more out of the small percentage who already donates.