The ATP2B1 gene affects the regulation of calcium in the body. The gene codes for the plasma membrane Ca2+ ATPase which is a transporter than allows for ions (charged molecules), Ca2+ in this case, to pass through membranes of the cell. Membranes are essentially barriers that compartmentalize cells from different fluids and spaces in our bodies. It allows for different environments to be created suited for different enzymes and processes. The term plasma means that it is an external membrane – it is facing the outside of a cell. Because of membranes, our body can regulate the movement of different molecules in and out of the cell as they are needed. This transport protein regulates the amount of calcium moving in and out of cells. If calcium is needed in the blood, or it is not needed in a specific cell, the protein acts as a pump to move calcium ions out of the cells. If there is a lot of activity in the cell, or calcium is needed in signalling, calcium may be pumped into the cell. It is activated when vitamin D binds to the transporter, therefore, vitamin D can actually impact the movement of calcium in your body.
However, ATP2B1 actually puts you at risk for low levels of magnesium:
Although the ATP2B1 codes for a calcium transporter, certain alleles of this gene can increase the risk of hypomagnesmia (low levels of circulating magnesium) in the blood. It is thought that there is an indirect effect as there is evidence to show that increased intake of calcium and other minerals decreases the absorption of magnesium. However, the cause and mechanism behind this of this remains unclear.
The G allele, has been associated with lower levels of magnesium in the blood. The G allele is found in 29% of the general population and it increases risk for hypomagnesemia by 24%.
The TRPM6 genotype also increased the risk for hypomagnesmia so if you are carrying risk alleles for both these gene variant, you may want to be more conscious of magnesium intake and reflect on any lifestyle factors, such as excessive alcohol consumption, that may inhibit absorption or deplete stores of magnesium.
However, as with other genes, having these alleles in isolation is no cause for alarm. If you are healthy and generally well, there in no need for concern. If you are worried, or have been feeling ill, do talk to your GP or a dietitian before starting any major dietary changes or supplementation.
Magnesium and its sources:
Calcium and other factors affecting magnesium absorption: