South Florida Sun-Sentinel Palm Beach (Sunday)
Consuming 64 ounces water daily could be ‘unscientific’
Q: We have heard for years that we are supposed to drink eight 8-ounce glasses of water every day. Yet, no one has ever bothered to tackle the other side of that equation. That is 64 ounces of liquid with perhaps many more from other sources throughout the day.
How many times am I going to go to the bathroom during the day and night? I don’t think that all this liquid can be eliminated before bedtime. Some inevitably filters through and causes nighttime bathroom jaunts.
A: There has been a great deal of confusion about the “8 x 8” (8 ounces of water, eight times a day). Some researchers call this recommendation unscientific. Others point out that you get liquid from other sources besides drinking plain water (Nutrients, Oct. 31, 2020).
Older people may be vulnerable to dehydration if they don’t drink enough fluid, especially during hot weather. On the other hand, your point is pertinent that drinking a lot of water will result in a lot of nighttime trips to the bathroom.
Q: Many years ago, I complained to my doctor about restless legs. She prescribed folic acid (1 milligram daily). It has to be prescription, not over the counter. It works! A: Folic acid is a B vitamin. The 1 milligram dose is available both by prescription as well as over the counter. The recommended daily allowance is 400 micrograms, less than half the amount you are taking.
Some researchers say the recommendation of 8 ounces of water, eight times a day, is unscientific.
We searched high and low and could find no good evidence to support the use of folic acid supplements to treat restless leg syndrome. Many doctors consider this supplement innocuous, since B vitamins are water soluble.
There is one caution, however. A recent study based on data from the U.K. Biobank found an unexpected link between prescribed folic acid supplements and susceptibility to COVID-19 (BMJ Open, Aug. 24, 2022). Even worse, people who caught COVID-19 while taking high-dose folic acid were more than twice as likely to die of the infection. The authors suggest that this B vitamin may make it easier for the virus to multiply.
Q: You’ve written about the possible benefits of vitamin D to boost immunity and protect people from infection. So perhaps you won’t like this at all. There are studies showing that vitamin D does not help prevent COVID-19! What do you think?
A: Thank you for bringing this research to our attention. Both studies were recently published
in the BMJ. One of the studies included 6,200 British adults who had not been taking vitamin D (BMJ, Sep. 7, 2022). The researchers tested blood levels of the study volunteers and assigned them on a random basis to get vitamin D supplements or not. During the six-month follow-up period, people taking vitamin D were no less likely to come down with a respiratory tract infection, including COVID-19.
The other study was conducted in Norway (BMJ, Sept. 7, 2022). The scientists recruited more than 34,000 people who were not taking vitamin D supplements. Half of them were given cod liver oil and the other half placebo, taken daily during the winter. Cod liver oil contains vitamin D (10 mcg or 400 IU per daily dose). These supplements did not reduce the participants’ chance of contracting COVID-19 or other respiratory infection.
In their column, Joe and Teresa Graedon answer letters from readers. Send questions to them via www. peoplespharmacy.com.
Q: For years, I have been hearing about the advantages of taking CBD products for sleep, pain and just about anything that ails you. I now see these products everywhere being sold over the counter in drug stores. Is CBD beneficial, and does it live up to its claims? A: CBD is one of the main cannabinoids found in cannabis plants. Products made with CBD in the U.S. retail market should not contain THC, the psychoactive ingredient in marijuana that produces a high. These products are supposed to be only derived from the marijuana strain cannabis sativa, which naturally has less than 0.3% of THC.
CBD is available by prescription or as an added ingredient in many overthe-counter products. These products are legal at the federal level as long as the CBD is derived from a cannabis sativa plant grown in the U.S. from a company with a specially issued license. The products are illegal if derived from the higher THCcontaining cannabis indica strain or a sativa plant not grown in the U.S.
Although CBD claims to have many beneficial effects, the Food and Drug Administration classifies it under its orphan drug designation. This is a special designation that must meet criteria of therapy for a rare disease or is used so infrequently that it may not be a profitable product.
CBD has primarily been marketed as an anticonvulsant agent for rare seizure disorders, though some newer indications are being investigated.
At this time, nonprescription CBD products lack oversight to ensure their purity and safety, or to verify manufacturer claims. The CBD that you can buy over the counter is regulated more like herbal supplements than medications. This is because the FDA only enforces quality and safety standards if a safety issue arises once a product is on the market.
The standards for CBD products, like herbal supplements, are based on manufacturers making ethical claims. You cannot rely on the amount of CBD listed unless assessed by an independent party such as the United States Pharmacopeial Convention. You also cannot be assured that CBD is free from contaminants such as THC, pesticides or heavy metals.
At this time, CBD cannot be rated for any condition other than epilepsy due to lack of evidence, even though it is used for many other conditions.
CBD is a depressant, so it can make you drowsy. However, its long half-life of 50-60 hours makes it undesirable as a sleep aid. Half-life is defined as how long half of the drug is eliminated after one dose. Sleep aids are best suited to medications with shorter half-lives, so drowsiness is not experienced the next day. Other common side effects are decreased appetite, fever, anemia, fatigue and gait disturbances.
The highly touted pain relief indication of CBD has not been shown by current research.
CBD is metabolized in a complex way by many enzymes while it interferes with other enzymes that metabolize other drugs. Use CBD carefully if you take other medications.
While research is ongoing into CBD as a treatment for a wide range of conditions, including cancer, hepatitis, Parkinson’s disease, diabetes and some psychiatric disorders, future indications may result in CBD not being classified as an orphan drug.
Until better evidence indicates that more common uses are safe and effective, CBD will continue to be a product that lacks evidence to support claims of efficacy for many conditions.
Before you try nonprescription CBD for any medical concern, speak with your health care provider about whether it would be safe and effective for you. Your provider may be able to help you determine which product to purchase.
— Michael Schuh, Pharm.D., R.Ph., Pharmacy, Mayo Clinic, Jacksonville, Florida
Mayo Clinic Q&A is an educational resource and doesn’t replace regular medical care. Email a question to MayoClinicQ&A@ mayo.edu.