Taking Vitamin K2, Although Safe, Doesn't Prevent Osteoporosis
DEAR DR. ROACH: I'm a 68-year-old female who is in good health. I currently take vitamin D3. The only prescription that I'm on is rosuvastatin. It has been brought to my attention by my cousin, who is a devout vegan, that taking vitamin D3 with K2 is much better than just taking D3 alone. If this is true, I'm wondering why my doctor hasn't recommended it.
When I mentioned this to my friends, they had never heard of D3 and K2 either. Do you see an advantage to switching over to this supplement? I had a bone density test done this past year, and the doctor said that there were no problems. -- W.R.
ANSWER: In my opinion, supplements can be a way of treating symptoms and some medical conditions. But there are very few situations in which a supplement is proven to be effective at preventing problems for a person who feels well.
Vitamin D3 may be one exception as it is important to prevent and treat osteoporosis for those who are at risk. While I often hear that vitamin K2 is effective for osteoporosis (probably based on a Japanese study), several studies in the United States failed to show any significant benefit of it over a placebo. So, I do not recommend vitamin K2 for people with osteoporosis, nor do I recommend K2 to prevent it. Since you don't have osteoporosis based on your bone density test, you would be taking it for prevention.
Vitamin K2 is being evaluated in helping to reduce heart disease risk, but the evidence isn't strong enough yet to recommend it. Vitamin K2 is very safe, and I don't object to people using it, although they are likely wasting money.
DEAR DR. ROACH: Outside of limiting your salt intake, avoiding potassium and phosphates, and hydrating properly, is there anything that one can undertake to stop or reverse declining kidney function? -- H.M.
ANSWER: The answer depends on the underlying reason for the chronic kidney disease (CKD) and how much the disease has progressed. Limiting sodium, potassium and phosphates is good general advice for most people with CKD. It's also important to avoid drugs that stress the kidney. The most important classes of drugs to avoid are anti-inflammatory drugs, like ibuprofen and naproxen, and the many prescription drugs in the NSAID class.
Medical procedures with dye should be avoided if possible, and some antibiotics are problematic. So, it's important for all your doctors to know about your kidney disease.
Blood pressure control is important for everyone with CKD. Some medicines for high blood pressure (such as ACE inhibitors and angiotensin receptor blockers) are more protective of the kidney than others, so it's worth asking your regular doctor or kidney specialist if your medicines are optimal. People with diabetes should also keep their blood sugar in the optimal range as much as possible.
In people with CKD and high levels of protein in their urine, the use of SGLT2 inhibitors (such as dapagliflozin or empagliflozin) has been proven to slow the progression of kidney disease by almost 30%. People with CKD who smoke should stop. Modest protein restriction remains controversial, but I advise it for my patients with CKD.
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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu.
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