If it has been recommended that you take these tablets across the duration of a day, then it is absolutely essential that you follow the direction properly. Sometimes, there are very specific reasons for these types of instructions. It is possible that all of the calcium may not be absorbed if the tablets are taken at one go, and this is the reason why you have been asked to split the dosage. It is also possible that the effectiveness of the drug will decrease if you take all the pills together. Sometimes, if you consume an excess of anything and it does not have the time and space to get absorbed in your body, it is simply flushed out of your system via urine or stools.
Sometimes, the reason why doctors recommend that you take the pills across a certain time period is that some medicines also cause other side effects. For instance, if taken together, the pills may cause acidity. This could be a prohibitive reason as well. Sometimes, it is possible that you may also suffer from heartburn if you take all these pills together. If you are faced with the problem of forgetting to take these pills, then a better solution would be to take them before going to bed at night. This way, if there are any side effects, you will not really feel the worst of them. However, it is important to check with your doctor before you start taking them all together.
answered by M W