Ask the doctor.

A few years ago, I got a pulmonary embolism and deep vein thrombosis (DVT). Is it possible for me to take too many supplements that can thin the blood too much? Sometimes when I bump myself, a bruise forms.

--Dan, via email

Let's go back to the original incident of DVT. We tend to think of the human body as a piece of heavy equipment made to function normally with a lot of abuse. But I consider the human body to be more like the sensitive engine of a fine sports car. It does not do well with sudden changes, but it eventually adapts to them. What's more, both fatigue and your diet for the preceding 24 hours could have encouraged clot formation.

DVT is common for travelers who are forced to sit for extended periods. That's why on long driving trips you should stop at regular intervals and move your legs. When you're on an airplane, you should take a walk down the aisle every hour or so.

As for diet, avoid foods that encourage clotting such as spinach, broccoli, asparagus, milk, soybeans, sugar, saturated fats and red meat. Instead, eat chicken, fish, peppers, onions, ginger, garlic, tomatoes and brightly colored fruits and vegetables. These contain natural coumadins, which discourage clotting.

As for supplements that may mitigate clotting, it is possible to take such high dosages that you braise easily. But I think it is more likely that your digestive function is weak.

In traditional Chinese medicine, bruising occurs from a weak "spleen." The spleen, in this context, is essentially the pancreas, the top of the small intestine and ...