Older parents' supplements and medicines: what to check?

Before adding any supplement for an older parent, make one list of every medicine, supplement and herbal product they use, and show it to their doctor or pharmacist. Many older Thai people already take several medicines: a study of 587,905 people aged 60 and over at 46 hospitals in northeastern Thailand found that 59.5% used five or more for at least 90 days in a row. Herbs and supplements are often used alongside them, and the same vitamin or mineral can come from more than one product. The US National Institute on Aging (NIA) says older adults who take many medicines are at additional risk of side effects, and that mixing certain medicines and supplements can be dangerous.

In short:

• First: one list of everything, shown to a doctor or pharmacist
• Look for overlaps: the same nutrient in a multivitamin, a single-nutrient product and some medicines
• Use the upper limits: they count the total, not one product
• Get help quickly: if a medicine seems to cause problems, call the doctor; for a possible wrong dose, the Ramathibodi Poison Center is on 1367

For everyday food, water, movement and sleep for older parents, see My older parents often feel unwell. What can we do each day?

How many medicines do older Thai people take?

Taking five or more medicines at the same time is common among older Thai people who use hospital services.

What these numbers can and cannot tell you

The first study covered older people who came to hospitals in one health region, and the authors say the results should not be applied to all rural older people. The second was small. Both counted medicines from records and visits, so they say nothing about herbs or supplements bought separately, which is the next part of the picture.

Do older Thai people also use herbs and supplements?

Why the doctor may not know

The Hat Yai study shows the gap: most users had never been asked about herbs by a health professional. If you do not mention them, the person reviewing your parent's medicines sees only part of what goes into the body each day. The two studies were in single provinces, and the Chonburi data are from 2008.

Why does mixing many products matter?

What public health bodies say

• The NIA says that older adults often have several health conditions and may take many medicines, which puts them at additional risk of side effects, and that combining certain prescription drugs, over-the-counter medicines, dietary supplements or other remedies can be dangerous.
• The US Food and Drug Administration (FDA) says certain dietary supplements can change the absorption, metabolism or excretion of a medicine.
• The NIH Office of Dietary Supplements (ODS) says side effects are most likely when supplements are taken at high doses, instead of prescribed medicines, or when someone takes many different supplements.

Leftover medicines at home

Vatcharavongvan and Puttawanchai of Thammasat University interviewed 19 patients aged 60 and over in Pathum Thani in 2015, each taking five or more medicines, and photographed where they kept them. Most used up leftover medicines without looking at the expiry date, and leftovers were kept, shared, thrown away or returned. It was a small study, but it describes things families can check in their own homes.

What a poison centre sees

Monkaew and colleagues reviewed calls to the Siriraj Poison Control Center from 2020 to 2023. Of 5,146 cases, 682 involved people aged 60 and over, and medicines accounted for 45.8% of their exposures. Among unintentional exposures to medicines, the most common cause was a side effect or an interaction between drugs (56.8%), followed by using a medicine by the wrong route (20.8%). These are cases reported to one centre, not a measure of how often this happens at home.

How can the same vitamin or mineral come from several products?

Multivitamins and single-nutrient products

The ODS fact sheet on multivitamin/mineral supplements says that taking a multivitamin increases the nutrients you get each day, but can also raise the chances of getting too much of some, such as iron, vitamin A, zinc, niacin and folic acid. It advises anyone who eats fortified foods and drinks or takes other supplements to make sure the multivitamin does not push their intake of any vitamin or mineral above the upper limits.

Medicines that contain minerals

The ODS also notes that some over-the-counter antacids contain calcium carbonate, and that magnesium is included in some laxatives and some products for heartburn and indigestion. These count towards the same totals.

Upper limits for the nutrients these sources name

Use this table to check the combined amount from several products, not as a list of what to take. It covers only the nutrients the ODS names above: the five a multivitamin can push too high, and the two found in some medicines. The upper limits are US values for adults published by the ODS, and they do not all count the same sources.

Source: ODS consumer fact sheets on iron, vitamin A, zinc, niacin, folate, calcium and magnesium.

How to use the table

Add up the amount of each nutrient on every label your parent uses, then ask the pharmacist to look at the totals with you. The NIA notes that more is not better: it can be harmful to take too many supplements or ones with a very high concentration of a nutrient.

How do I make a medicine and supplement list for my parent?

What to write down

Where to keep it and who to show

The NIA suggests showing the list to all of your parent's health providers, including dentists and physical therapists, keeping one copy at home and one in a wallet or purse, and filling all prescriptions at the same pharmacy where possible so records are in one place. The FDA advises bringing the list every time you visit a health professional.

Other things to check at home

The NIA also suggests learning to tell each medicine apart by size, shape, colour or the number on the pill, keeping the leaflets that come with each medicine, checking expiry dates and asking a doctor or pharmacist how to get rid of unused or expired medicines safely.

My parent wants to start something every day. Where should we begin?

Start with the list, not a new product

The NIA says to talk with a health provider before starting any new prescription, over-the-counter medicine or supplement, and to make sure the provider knows everything else your parent is taking. It also advises not starting a supplement for any health problem without checking with a doctor first.

Food first

The NIA says eating a variety of healthy foods is the best way to get the nutrients you need. The NIA page on supplements for older adults adds that "natural" does not mean safe, and that a supplement might make a prescribed medicine weaker or stronger. The day-to-day checklist of food groups, water, movement and sleep is in My older parents often feel unwell. What can we do each day?

When should I call a doctor or pharmacist?

Call the doctor

The NIA advises calling the doctor right away if your parent has any problems with a medicine or you are worried it might be doing more harm than good. It also says not to stop taking a medicine before talking with a health provider, and to write down side effects so they can be reported accurately.

If your parent may have taken the wrong medicine or too much

In Thailand, the Ramathibodi Poison Center at Mahidol University answers calls on 1367, 24 hours a day.

Before any operation

The ODS says some supplements can change the response to anaesthesia if taken before surgery, so tell the doctor about every supplement if an operation is planned.

If your parent takes regular medication, talk to a doctor or pharmacist before adding any dietary supplement.

Dietary supplements are not intended to prevent, treat or cure any disease.