WebMD Ask the Pharmacist

Taking Vitamins and Supplements: Ask the Pharmacist

Pharmacist Heather Free, PharmD, answers questions about top vitamins and supplements.

Question:

I have shellfish allergies. Can I safely take fish oil capsules?

Answer:

When it comes to medication products, it is important to read all product labels carefully before purchasing and consuming any item. Consult the local pharmacist to help make sure no shellfish materials are found in the product. Remember, also, that ingredients change from time to time. So check labels every time you shop.

Fish oil products usually come from oily fish, such as salmon, trout, swordfish, and mackerel. Particular products that are EPA and DHA derived come from the “omega-3” sources tend to be more bio-available, making the product more effective to provide the cardiovascular effects desired. Shellfish are typically not used to make the fish oil products. However, it is important to read all ingredients on the bottle. Call the manufacturer to make sure there are no shellfish ingredients.

Once you find a particular brand that works for you, stick with it. But continue to check the label to make sure nothing has changed with the product.

Question:

Is it possible that my new onset of severe gas pains is caused by my recently starting to take a B12 OTC supplement? I also take an antidepressant.

Answer:

It depends on the form of vitamin B12 you are taking. Gastrointestinal side effects associated with parenteral cyanocobalamin or vitamin B12 given by injection have included dyspepsia, nausea, vomiting, and mild transient diarrhea. These side effects are very mild or not present at all with oral vitamin B12. If you are experiencing severe gas pains that have not subsided within a few hours, you should consult your health care provider.

Question:

Is Vitamin Water helping the body as much as it advertises?

Answer:

There are indeed a variety of vitamins in any flavor of Vitamin Water. But it seems the benefits of vitamins are offset by the effects of sugar. There are 13 grams of sugar in one serving, so an entire bottle contains about 32.5 grams of sugar. In addition, Vitamin Water contains between 100 to 125 calories. In comparison, a can of Coke has 140 calories.

The best thing to do is to drink regular water and get vitamins from a good source of fruits and vegetables. If you can't change your diet because of medical reasons, convenience, or availability, a wide range of vitamin supplements are available in pill or liquid form.

Question:

If I have calcium pills and/or vitamins that are expired for almost a year now, are they still worth taking or are they no good now? Do vitamins and minerals need to be thrown away after expiration on bottle?

Answer:

Never take products that are expired. We wouldn’t drink milk two weeks past expiration dates. Just because the pill doesn’t have an odor or appear different to the eye does not mean that it cannot have harmful effects to the body. Some medications lose the effectiveness of the intended outcome, while others can be converted to a different form that can be harmful. Every medication or product, whether it is over-the-counter or prescription medication, should be properly disposed of after it has reached its expiration date.

Question:

Can taking a spoon of distilled vinegar three times a day replace a high blood pressure medication?

Answer:

Numerous studies have shown the positive effect of cider vinegar on blood pressure. Certainly, adding vinegar to the diet is a lifestyle modification, such as diet and exercise, which are all considered treatments to aid in blood pressure control. It is important to use this information as a supplement to diet, not a replacement for a medication. Blood pressure is a silent killer. You may not know how severe the effects are to the heart or other parts of the body. Keeping blood pressure under control is the key to prevention of further complications. Work with your health care provider to determine the correct medication and therapy for you to effectively keep blood pressure under control.

Question:

Is there a danger of taking too high a dosage of vitamin D?

Answer:

Everything that we consume, whether it is food, medication (prescription and over the counter), or a supplement (vitamins and herbals), can have toxic side effects if you take too much. The side effects can vary per product. Vitamin D is needed to aid in absorption of calcium. High levels of vitamin D can lead to high levels of calcium, and symptoms include nausea, vomiting, constipation, poor appetite, weakness, confusion, and kidney stones. To treat toxicity, seek medical advice and discontinue the use of the product until advised by your health care provider to resume use.

Question:

Does taking Vitamin B12 cause any side effects, like nausea?

Answer:

There aren’t too many side effects associated with common use of vitamin B12. The side effects that we are aware of, especially at high doses, are diarrhea, peripheral vascular thrombosis, itching, transitory exanthema, and urticaria. Gastrointestinal side effects associated with parenteral cyanocobalamin or vitamin B12 given by injection have included dyspepsia, nausea, vomiting, and mild transient diarrhea. These side effects are very mild or not present at all with oral vitamin B12. Again, the side effects can occur, but usually at higher doses.

Question:

What are the best vitamins for a pregnant woman?

Answer:

Taking multivitamins during pregnancy is extremely important for proper fetus growth and development. The RDA has recommended values of how much of each vitamin and mineral is recommended during pregnancy. There are many brands available on the market, as prescription strength and over the counter. Some are more tailored toward specific women lacking different components than others. A more expensive vitamin is not necessarily better than others. Work with your ob-gyn to help select a vitamin that will work best for you. Size and cost can play a role in the selection process, more importantly to aid in compliance.

Avoid taking several different supplements. Take one multivitamin that includes a variety of necessary nutrients in one dose. Combining supplements (such as taking a folic acid supplement along with your multivitamin, etc.) can raise concerns because you run the risk of overdosing on a particular nutrient. Taking more than twice the RDA of any nutrient should be avoided during pregnancy.

Question:

I am taking a multivitamin and a 1,000 D3 additional pill daily. Yet a recent vitamin D screening returned that I have a marginal low D level (25). What may this be caused by? Additionally, I am taking Asacol and Avodart for colon and prostate health. Thank you.

Answer:

Vitamin D is a fat-soluble vitamin that is better absorbed with a fatty meal or substance. If you are not aiding with the absorption of the vitamin D, then your body may not be taking in the amount of vitamin D that you have ingested. Depending on your other labs or additional health conditions, it is hard to determine the cause of your vitamin D absorption issues. Work with your health care provider to find a more detailed cause for the low absorption of vitamin D.

There are no drug interactions with the two medications that you are taking. However, this doesn’t necessarily mean that drug interactions do not exist. Consult your pharmacist to make sure it is still safe to take everything together.

Question:

I've had two cerebral hemorrhagic strokes. Should I avoid multivitamins with vitamin E or K?

Answer:

Consult your health care provider.

Question:

I am taking ferrous gluconate supplement because I am low on iron. My doctor wants me to take 2 tablets per day. My stomach cannot handle iron at all. Is there any alternative or different form of iron? And what would the difference be?

Answer:

Iron alone is harsh on the stomach. Ferrous sulfate rather than gluconate is more commonly used and in an enteric coating to help decrease the tendencies of upset stomach. Take the medication with food. You also can take it twice daily rather than two tablets at once. In addition, the slow-absorption iron may aid in decreasing the upset stomach effects.

Question:

Is it safe to give my child an antibiotic when she is taking an iron supplement? How long should I wait between giving one or the other?

Answer:

Iron supplements can interact with certain antibiotics such as tetracyclines, Cipro, Noroxin, and Levaquin. The type of antibiotic your daughter is taking determines whether the iron should be taken at a different time of day or not at all. Your daughter may just need to stop taking the iron while she is taking the antibiotic and then continue with the iron once the antibiotic is finished. Work with your pharmacist to make sure it is all right to take both.

Question:

What are the side effects of Estroven? What would be the best supplement for a woman to take to alleviate menopause symptoms?

Answer:

Estroven contains many vitamins, such as vitamin E, thiamin, riboflavin, niacin, vitamin B12, and folate. In addition, it contains calcium, selenium, boron, isoflavones from soybeans, and black cohosh. The black cohosh is thought to be the ingredient responsible for decreasing menopause symptoms, such as hot flashes. It is ranked by the natural medicines comprehensive database as “possibly effective.” The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. Therefore, this ranking is based on the little studies and information that we have available about this herbal. It is important to check and make sure there are no other interactions with additional medications that you may be taking and that it may not work for everyone.

The most common side effect for black cohosh is gastrointestinal upset, with additional less common side effects of rash, headache, dizziness, weight gain, feeling of heaviness in the legs, cramping, breast tenderness, and vaginal spotting or bleeding. Remember, black cohosh is not the only component to Estroven. Therefore, there may be other side effects that can occur based on the other ingredients. However, the black cohosh side effects are the most common.

Work with your ob-gyn and your pharmacist to look at other options that maybe more individualized for you.

Question:

When is the best time to take vitamins, in the morning or at bedtime?

Answer:

Multivitamins are not stimulants; therefore, they will not keep you up at night. Being compliant is important. If it works best for you in the morning, then take it with breakfast. If bedtime works better, that is what works best for you.

Keep in mind that fat-soluble vitamins, such as vitamins A, D, E, and K best absorb with fatty meals. This may affect when you take the supplement to get the most effectiveness.

Question:

Can you take too much magnesium or potassium?

Answer:

Both magnesium and potassium are used for many different biological reactions within the body and are vital for life. However, just as other elements and vitamins, there is a range that is important for functioning. Too little, and the body doesn’t function. Too much can cause toxicity issues and side effects. At too high enough levels it can be dangerous to the body.

Dietary magnesium does not pose a health risk, however pharmacologic doses of magnesium in supplements can promote adverse effects such as diarrhea and abdominal cramping when taken in excess. Risk of magnesium toxicity increases with kidney failure, when the kidney loses the ability to remove excess magnesium. Very large doses of magnesium-containing laxatives and antacids have been associated with magnesium toxicity. Symptoms for hyperkalemia, or too much potassium, include irregular heartbeat, nausea, and slow, weak, or absent pulse. Ultimately, too much potassium can stop the heart.

It is important to take all medications, prescriptions, and over-the-counter medications as directed and never self-medicate more than needed in order to prevent overdosing.

Question:

Is there iodine in flaxseed oil? I am allergic to iodine.

Answer:

It is important to read the bottle, looking at active and inactive ingredients, to make sure that it doesn’t contain iodine. If you are still unsure, check with your pharmacist to make sure that it is all right to ingest. I also recommend calling the manufacturer to make sure iodine is not listed as a component. Better safe than sorry!

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