DEAR DR. ROACH >> I am having trouble finding a reliable recommendation for the daily supplement zinc. I purchased 50-mg pills, but I think this may be too much. I am 74 and female, and I would like to include zinc in my daily supplements, as my hair has begun thinning quite a bit, straight down the top of my head.

— R.M.

Dear R.m. >> Zinc is an important nutrient, and it is certainly true that zinc deficiency may lead to hair loss. However, most people with hair loss do not have a zinc deficiency, and there are no convincing data that giving extra zinc to a person with normal zinc levels will help with hair loss. Hair loss along the midline is consistent with female pattern hair loss, which is very common among women in their 70s and usually has nothing to do with zinc.

Very high amounts of zinc supplementation can be dangerous (and impair your body’s ability to absorb other trace metals such as copper), but 50 mg is a safe amount. Still, the most effective therapies for female pattern hair loss include minoxidil (usually topical, but low-dose oral is increasingly used), spironolactone, and finasteride. A dermatologist is the expert on hair loss and can give you a better diagnosis by exam than I can by your description.

DEAR DR. ROACH >> My youngest son has to have both of his hips replaced. He is only 37, but is in a very strenuous job of being a boilermaker in an oil refinery. This is the hardest job in a heavy industry. His doctors are telling me that his hips deteriorated due to alcohol consumption — is this even possible? Even if he can get through this ordeal, he is still locked into this physical type of work.

The doctors say he will need another hip replacement in 10 to 15 years if he stays in this line of work. Do you agree with these statements?

— B.M.

Dear b.m. >> Let’s take them one by one.

The most common cause of hip disease requiring hip replacement is osteoarthritis of the hips, but it is quite unusual to see someone of your son’s age require a hip replacement. Alcohol is not a recognized risk factor for osteoarthritis of the hips, but alcohol is a known underlying cause of a much less-common condition: osteonecrosis of the hips, also called avascular necrosis.

The more a person drinks, the more likely they are to get this rare condition, even though most heavy drinkers will never get this condition. Not every person with osteonecrosis of the hip will require a hip replacement. It is frequent to have both sides of the hip with disease.

Untreated congenital hip dysplasia may also lead to severe hip damage requiring a total hip replacement, and it is also one cause I see in a person of your son’s age.

Prognosis after a modern hip replacement is very good. More than 90% of people are doing well, pain-free and without complications 15 years after surgery. Of course, some kinds of activities, such as heavy lifting and high-impact movements, could make the surgical prosthetics wear out faster, but regular activities such as walking, stair climbing, and most sports that are not high-intensity or high-impact can be done without damage to the prosthetic.

Although further alcohol use will not affect the prosthetic hips or other bones, many other body systems are very much affected by alcohol. So, if he has been a heavy drinker, it is time to stop. His doctors can help him find many of the available resources.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.