Discount brokerages require a minimum age of 18. However, you can create a sub-account under your dads name (as long as he signs some sort of consent form) and these sub-accounts don't have a minimum age requirement.
Vitamin D deficiency rickets can be caused by a lack of vitamin D in the diet, a lack of exposure to the sun, or malabsorption syndromes in which there is an inability of the intestines to adequately absorb nutrients from foods.
Symptoms of D Deficiency. Most people with low blood levels of vitamin D don't notice any symptoms. A severe deficiency in adults can cause soft bones, called osteomalacia (shown here). The symptoms include bone pain and muscle weakness.