Citrus trees need full sunshine and plenty of water, occasional feeding and warm winter temperatures
Having your soil tested will give you the best answers about the availability of micro nutrients in the soil.
Leaf and fruit buds form at the same time on a Blood Orange tree, and cold weather can damage some or all of the buds.
Your tree can end of with all leaves.
To help correct this you can prune the tree back hard to encourage new wood, this will encourage the tree to produce the right amount of leaves and fruit.
Here are some links with more information.