Use reliable literature sources for information about vitamins

Dear Dr. Roach: Would you recommend the most reliable literature source(s) for vitamin and supplement information and interactions? For instance, health magazines give these examples of supplement information:

• Take magnesium with vitamin D3 for best absorption.

• Do not take magnesium with zinc or iron supplements. Take it hours apart to avoid poor absorption of the zinc and iron.

• Take piperine with turmeric/ curcumin to enhance their absorption.

• Take vitamin D3 when taking calcium to improve absorption.

J.L.

The problem with health magazines is that reliable information can be interspersed with information that isn’t so reliable. Sometimes a claim is hopeful and based on experimental or animal data; sometimes it is demonstrably false, either by error or to sell an advertiser’s supplements. For the examples you mention above, vitamin D (D2 or D3) improves absorption of calcium and magnesium, but this doesn’t mean that you need them. I don’t recommend them unless they’re prescribed.

Piperine absolutely increases the absorption of curcumin, which is the most active ingredient in turmeric. This increases both effectiveness and toxicity. Zinc and iron compete for absorption, so they should not be taken at the same time; if you are deficient, they should be separate.

The first literature source that I recommend is MedlinePlus.gov, which is curated by the National Library of Medicine. Some large institutions, like Johns Hopkins and the Mayo Clinic, have highly reliable information. Your local pharmacist is another source, as is your own physician.

Dear Dr. Roach: I just read an article stating that the Centers for Disease Control and Prevention is now recommending that seniors 65 and up get an additional COVID vaccine. The article says that the current version is highly effective. I got my last Moderna vaccine in October 2023. Should I get another?

J.L.I.

I strongly recommend another vaccine this spring for those at a high risk, including those who are over 65 with additional risk factors like diabetes, heart or lung disease, and those who live in a nursing home. People who are considerably older — in their 80s or more — would also benefit from an additional vaccine this spring, even if they are otherwise healthy.

The data are becoming clear that an annual vaccine for COVID-19 is effective. While it isn’t yet proven, it may be that higher-risk people can benefit from getting vaccines twice a year. In my opinion, those at a very high risk, such as the people I mention above and people with immune system disorders, should take an extra vaccine now.