The risks of taking a loading dose of vitamin D-3 include bone loss, cardiovascular problems and kidney problems, according to SF Gate. The body is unable to dispose of excessive calcium, resulting in poisonous buildup of the mineral.
Taking too much vitamin D-3 increases the levels of calcium in the blood and results in calcification, which is the accumulation of calcium deposits in the lining of the blood vessels and walls of the heart, as noted by SF Gate. Calcification can cause cardiovascular or heart disease and limit the heart function.
Vitamin D-3 aids in balancing calcium levels in the body and maintaining calcium tissues such as bones, as explained by SF Gate. Excessive calcium in the blood can lead to loss of the mineral from the bones, making them weak, hard and increase the chances of bone injuries. This may lead to bone loss and fracture.
Increased amounts of calcium in the blood as a result of high consumption of vitamin D-3 may cause calcium to crystallize in the tubes of the kidney and form kidney stones, as stated by SF Gate. High levels of calcium in the blood stream can cause the kidneys to strain and reduce their function.