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When is the Best Time to take my Supplements

When is the Best Time to take my Supplements?

Most of us take more than one supplement and many of us take one or more prescription drugs. One of the most frequently asked questions  concerns the timing of medications and supplements and it can be very confusing.  To make matters worse, some of the labels of supplements make no sense at all telling us to wait 2 hours before or after a meal or in one case two manufactures of the exact same product have totally different directions. The product, Genacol, used for arthritic and joint pain recommends 3 capsules on an empty stomach either last thing at night or first thing in the morning. Their competitor, Nutri-Collagen recommends 2 in the morning and two in the evening with food. How far apart can you get?

In this article I will try and explain the reasons for taking supplements or drugs with food, on an empty stomach and how many prescription drugs can interfere with the absorption of your supplements.


I start with Calcium because most of your inquiries are about Calcium and the warnings on the bottle that it can interfere with other supplements and medications.

In the first place Calcium supplements of all kinds MUST be taken with food. If you take your calcium supplement on an empty stomach you will actually run the risk of getting kidney stones. This happens because calcium taken on an empty stomach is eliminated through the kidneys. If your body is deficient in Calcium your kidneys will not allow your body to eliminate the calcium. The free floating calcium ions attach themselves to oxalates from other foods and form calcium oxalate stones in the kidney. When you take your calcium supplement with food it will be excreted in the feces and not wind up in your kidneys where it can form stones.

Calcium is also taken with food because of its potential to upset the stomach and calcium is usually combined with Vitamin D to transport it to where it is needed and magnesium to reduce the possibility of constipation, a side-effect of calcium.

When you make a plan about how you are going to take your supplements and prescription medications, you have to start with calcium taken at mealtime.


Now that you have decided to take your calcium with a meal suppose you also have to take an anti-inflammatory drug such as naprosyn with a meal but you know that calcium will interfere with the absorption of all medications especially if it is calcium carbonate. The carbonate form of calcium is also known as Tums a product that absorbs stomach acid along with almost anything else it comes in contact with.

If you take them together, your naprosyn becomes bound up in the calcium and it may take an hour before the calcium ions and the carbonate molecules are broken off by your stomach acid releasing the naprosyn into your bloodstream. You have simply delayed the process but you have not lost any of the potency of your prescription drug.

If you do have to take a number of prescription drugs in the morning you take them first thing along with your supplements and then at least one-half hour later you take your calcium with breakfast. This time gap allows the supplements and prescription drugs to leave your stomach before you eat food and take your calcium.

Many of you take prescription drugs that reduce acid output in your stomach such as Losec, Nexium, Prilosec or Pariet. These drugs interfere with the absorption of nearly all supplements, prescription drugs and calcium and should be taken about one hour after your calcium supplement, allowing everything before it to be dissolved in your bloodstream.


Most prescription medications and supplements work better when taken on an empty stomach because there are no food or drugs to interfere with their absorption. However, taking supplements on an empty stomach is not critical because if they are taken with food they simply have to wait for your stomach to empty and their absorption may be delayed by about one hour. You may lose some potency but only 10 percent of digestion takes place in your saliva and stomach so at least 90 per cent of your supplement will eventually be operating in your blood stream.


Most supplements such as multivitamins, Vitamin C, B Vitamins and calcium magnesium products are water soluble. This means that the individual dose will only last in your body for 4 to 6 hours. That means if you have a vitamin that requires you to take 3 a day, you must divide the dosage over the whole day. Taking 3 at once will do you no more good than taking one. This holds true for glucosamine supplements that must be taken 3 times a day and calcium supplements that must be taken two or three times a day. Water soluble supplements are usually recommended to be taken on an empty stomach, unless of course it is calcium.


Fat soluble supplements include Vitamin D, Vitamin E, fish oil and most forms of Coenzyme Co Q10. These supplements are delivered to the fat tissues of your body and stored there to be used when needed. This means that if you take 2 fish oil capsules a day, or two Vitamin D capsules a day you can actually take them together and not have to divide up the dose. They will be stored and released as needed when your body needs them. Coenzyme CoQ10 also dissolves in the fat tissues but lasts only about 12 hours. This means that if you are taking CoQ10 as an antioxidant for energy then one a day is enough. However, if you are taking CoQ10 for your heart then you should divide the dosage you take by taking one capsule every 12 hours.

With fat soluble products food in your stomach is not a factor. They can be taken with or without food and they will still arrive in your fat tissues ready to be released. However, once again, calcium interferes with everything and you always have to take your medications and supplements away from your calcium if possible.


Reactions between supplements and prescription drugs are really quite rare because of the very different ways your body treats these substances. When you swallow a prescription drug your body has no idea what to do with it. Your body then treats the drug as a foreign substance and sends it to the liver to be detoxified and rendered harmless. However prescription drugs are designed in such a way that when this process takes place in your liver it actually activates the drug and sends it out into your bloodstream to do its work. After 4 to 8 hours (the half-life of the drug) the remaining half of the drug is returned to the liver and the process is repeated sending a new active form out into the bloodstream.

When your body swallows food or supplements they contain recognizable ingredients that your body breaks down into nutrients. These substances are digested by your saliva, stomach acid and broken down into their component parts by enzymes in your upper and lower intestine. These ingredients are then transported to the different cells that require these ingredients.

Because these two processes are extremely different it is highly unlikely that any drugs and supplements interfere with each other. St.John’s Wort is one exception because it is detoxified by your liver by the same substance (cytochrome p450) that detoxifies drugs. Grapefruits are also detoxified at the same site and may also interfere with some medications.

The bottom line is that almost every drug interferes with every other drug because they are all detoxified at the same site in your liver. The worst culprits are Coumadin (warfarin) and Tylenol because they take longer to detoxify than most drugs and slow down the absorption of all the other drugs trying to get through the liver and into your blood stream.


I am going to create a drug and supplement profile for a typical elderly patient and try and show how that patient should be taking their prescription medications and their supplements.

A typical elderly person will take one or two meds for blood pressure, a diuretic along with these to further control their blood pressure and a cholesterol-lowering pill. My fictional patient will also be a female who takes fosamax for her bones and omeprazole to control her acid reflux and naprosyn 500mg twice a day for her arthritis.

On the supplement side she takes a calcium magnesium supplement, a multiple vitamin, fish oil, Vitamin D, Vitamin E and CoEnzymeQ10.

Morning: Before breakfast on an empty stomach she takes her blood pressure meds, her diuretic, one multivitamin, 2 fish oil capsules, 2 Vitamin D capsules and one CoenzymeQ10.

After having her morning coffee or tea, about 1/2 hour after taking her other meds she eats breakfast and takes her calcium supplement. About one hour after breakfast she takes her stomach medicine (omeprazole). Sure it would be better to take your stomach medicine first thing and avoid any stomach upset but this drug is very dangerous and interferes with the absorption of most other drugs including all her meds and her calcium.

Lunch: Our patient takes her calcium and her naprosyn with her lunch. The naprosyn, if taken in the morning would reduce the effectives of her blood pressure medications and so by taking it with lunch that contraindication is avoided but it will be about 2 hours before it begins to work.

Supper: One again we take the calcium supplement and she can also take her second capsule of Coenzyme Q10 because it is fat soluble and food will not interfere with it. After supper is finished she takes her cholesterol tablet which will be far away from any interaction with grapefruit and which must be taken in the evening because your body does not produce cholesterol until you go to sleep. Sometime later in the evening with a small snack she will take her 2nd naprosyn tablet and if she takes fosamax once a week, she will take it on an empty stomach first thing in the morning about ½ hour before breakfast because she should be upright for that ½ hour to prevent any damage to her esophagus after taking the fosamax.

If you think this regimen is confusing you are absolutely right.  If you try and work out a schedule with your pharmacist they probably will be more helpful than your physician who blames every interaction on supplements. If you want to be absolutely sure you are doing the right thing you bring your list into me and I will help you organize your supplement and medication schedule. There is no charge for this service but you must make an appointment.


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