Melatonin good for daily use?

Editor's note: This column originally appeared on Nov. 2, 2021.

DEAR DR. BLONZ

>> Is it reasonable to take melatonin daily as a sleep aid?

— B.S., Westmont,

Illinois

DEAR B.S. >> Melatonin is a hormone that plays a role in our sleep-wake cycle; it is produced by the peasized pineal gland located in the center of our brain. The release of melatonin is stimulated by darkness and inhibited by light.

The rationale behind taking melatonin as a sleep-aid supplement is that it might help shift your sleep-wake cycle to the new time zone. Some research supports this use, but most studies find that melatonin does not seem to be very effective for sleep disorders in general.

Most studies note an absence of adverse effects — especially when small dosages (3 milligrams per day) and short-term use are involved. However, keep in mind that melatonin is a hormone usually produced by the body, so unless specifically instructed by your physician, it is not something you want to be taking regularly. It is also a substance that can interact with other medications or supplements. If you do take melatonin, be sure to note it on your medical record for your pharmacist and other health professionals to consider. Find out more about melatonin and its uses at b.link/shvcqu.

DEAR DR. BLONZ >> What are your thoughts about all the dietary supplements made from dehydrated fruits and greens? These are supposed to be nutritionally identical to the real foods, minus the water and air (so they can fit in the capsules). A fivecapsule serving of the product I am considering is said to provide the same nutrients as five servings of fruits and vegetables. Are these a reasonable equivalent to eating the produce itself?

— F.F., Albany

DEAR F.F. >> Such supplements may have started as foods, but more than water and air get left behind in the manufacturing process. I don't know the specific product you are referring to, but some generic math will show how it would be physically impossible to provide five servings of fruits and vegetables in five capsules.

Servings are specific. According to the USDA, one serving of vegetables is 1 cup of raw, leafy vegetables; 1/2 cup of cooked or chopped raw vegetables; or 3/4 cup of vegetable juice. One serving of fruits is a whole fruit such as a medium apple, banana or orange; a grapefruit half; 1/2 cup of berries, melon or chopped raw fruit; 1/2 cup of cooked or canned fruit; 1/4 cup of dried fruit; or 3/4 cup of fruit juice. Using a modest estimate of 2 grams of dietary fiber in a single serving of a typical fruit or vegetable, we would have 10 grams of fiber in 5 servings. Check the Supplement Facts label on the product and see what is present.

Dietary supplements are not meant to replace food.