<prompt> All are true regarding fetal skeletal mineralization exceptApproximately 30g of calcium is needed especially during 3rd trimester.Calcium required by fetus is only 10 of maternal, skeletal calcium.Amount of calcium absorbed increases to 400mg day in the third trimester.PTH plasma concentration is decreased in first trimester, but increases progressively later.  <response>: Fetal calcium requirement is only 3 of total calcium held within maternal skeleton. 