Q: I recently got married to a man who had a vasectomy 2 1/2 years ago in a previous marriage. Well, I'm pregnant! My husband initially accused me of cheating on him, but I swore to him that I've not been with another man. It must be that his vasectomy failed. Aren't they permanent?

ANONYMOUS, Allentown, Pa.

(ENLARGE)

Dr. Mitchell Hecht

A: While a vasectomy is a highly effective method of birth control, it is not 100 percent effective. In fact, 2 in 1,000 vasectomies will fail at some point. This happens when the sperm-carrying tubes rejoin naturally. How can this happen? Well, there's such a powerful force in nature driving the perpetuation of our species that despite our attempts to limit our individual reproduction, our own body seeks to thwart such efforts. It's an amazing thing that surgically cut and tied off reproductive tubes can grow back together.

Urologists are aware of this potential problem, and the small risk of eventual failure should have been explained to your husband. It's strongly recommended that those who undergo a vasectomy submit semen specimens to look for sperm at six and 12 weeks after the vasectomy. When there are no sperm in two consecutive samples, an "all clear" is given to allow sex without the need for another method of birth control. However, even when the "all clear" is given, a very small risk of failure exists and can occur at any time (as you've discovered). Therefore, I'd suggest that a semen analysis be done periodically to ensure that no sperm have returned.

Q: I recall reading something a while ago about a connection between vitamin D and diabetes. Do you know what the connection is? I'm interested because I'm 66 years old and have been a diabetic for the past 14 years.

R.T., New York, N.Y.

A: I recommend that all diabetics ask their doctor to order a 25-hydroxyvitamin D level blood test. The reasons for testing your vitamin D level are several. 1) There is a higher risk of vitamin D deficiency in diabetics for unclear reasons. That'll place diabetics at higher risk of osteoporosis; 2) A low vitamin D level (an ideal 25-hydroxyvitamin D level is greater than 30) interferes with the proper function of insulin-producing cells, and vitamin D supplementation may be a factor in helping to control their diabetes; and 3) Folks who have diabetic nerve pain may achieve an analgesic (pain-relieving) effect from taking vitamin D supplementation. Folks who suffer painful diabetic nerve damage in the setting of vitamin D deficiency have an important reversible cause for at least some of their pain that they might not even know about.

Beyond diabetes, a low level of vitamin D may also be a cause of low back pain, worsening joint pain in folks with confirmed osteoarthritis, and nonspecific musculoskeletal pain. Getting your 25-hydroxyvitamin D level checked through a blood test is easy and inexpensive.

Dr. Mitchell Hecht is a Roswell physician specializing in internal medicine. Send questions to him at "Ask Dr. H," P.O. Box 767787, Roswell, GA 30076. Personal replies are not possible because of the large volume of mail.