Dear Dr. Gott: My doctors have told me that there are better times during the day to take vitamins or calcium. I take a thyroid pill in the morning. About an hour or so later, I take my vitamin with an omega-3 tablet and then take my calcium tablet with a late lunch or after my dinner. Am I taking them correctly as far as getting all the benefits from them? I hope you can answer this question for me.

Reply: You ask an extremely important question, and your doctors are correct in what they tell you. In some respects, the most appropriate time of day to take vitamins and other medications is when you are least likely to forget, such as the first thing each day.

Thyroid medication should be taken on an empty stomach a half-hour before breakfast. If you are a swing-shift employee, judge accordingly and plan to take the medication at an appropriate time.

Vitamins can be taken at almost any time of the day, so just before or following a meal is satisfactory. Be sure to read the recommendation printed on each vitamin bottle to determine what the manufacturer believes is most appropriate. There are some supplements that work better when taken on an empty stomach. For example, if B-complex vitamins upset your stomach, take them with food. Iron supplements should be taken on an empty stomach. And, whenever vitamins are consumed, do not wash them down with alcohol.

Calcium comes in two forms – calcium carbonate, which is more readily available and inexpensive, or calcium citrate. Either form should be taken at least four hours apart from any thyroid medication. This also holds true for calcium antacids, iron supplements and many drugs prescribed or recommended as antacids. Calcium carbonate should be taken with meals; calcium citrate can be taken either with meals or on an empty stomach. Calcium should be taken in 500-milligram doses or less at one time. Therefore, if your supplement is a 1,000-milligram tablet, split it into two doses, because it can hamper the absorption of some medications, including those for high blood pressure and antibiotics, so a timing modification might be required. Speak with your physician for his or her recommendations.

I do not believe there are any specific requirements for omega-3 fish oils. To the best of my knowledge, they can be taken at any time of day and either on an empty stomach or a full one.

Drugs, whether prescription or over-the-counter, can interfere with other medications. Their effect can be reduced, and they can also lead to gastrointestinal issues and a number of other problems. Make sure that your physician knows what supplements you are currently taking so he or she can guide you accordingly.

It appears to me you are diligently attempting to do the right thing at the right time.

To provide related information, I am sending you a copy of my Health Report 'Vitamins & Minerals'. Other readers who would like a copy should send a self-addressed stamped nymber ten envelope and a $2 cheque or money order to Newsletter, PO Box 167, Wickliffe, Ohio 44092-0167.

Dr. Peter H. Gott is a retired physician and the author of several books, including 'Live Longer, Live Better', 'Dr. Gott's No Flour, No Sugar Diet' and 'Dr. Gott's No Flour, No Sugar Cookbook', which are available at most bookstores or online.