Should I eat fish, or take fish oil supplements to prevent heart disease?

DEAR DOCTOR K: Heart disease runs in my family. Should I eat fish, or take fish oil supplements?

DEAR READER: Eating fish regularly reduces a person's risk of sudden death from heart disease. It's also brain-healthy. For that reason, I and most doctors recommend a regular diet of fish for people who have heart disease. And also for people like you where heart disease runs in the family. Fish oils are rich in omega-3 fatty acids, a kind of "healthy fat."

How seriously do I need to take prehypertension?

DEAR DOCTOR K: I'm in my 20s. My doctor says I have prehypertension. How seriously do I need to take this?

DEAR READER: Quite seriously. High blood pressure, or hypertension, is a blood pressure of 140/90 mm Hg or higher. Only a few decades ago, blood pressure lower than that was considered normal -- or, at least, not worth worrying about. But during the last 20 years, multiple long-term studies have shown that people with blood pressures higher than 120/80 but lower than 140/90 have an increased risk of heart disease and stroke.

How can I get rid of bloating?

DEAR DOCTOR K: I feel bloated and my belly looks larger than normal. Is this due to excess gas? What can I do to feel better?

DEAR READER: That feeling of fullness and tightness in the abdomen is called bloating. Distension is the term for the increased size of your abdomen. Excess gas is probably not to blame for either problem. It makes sense to think that bloating and distension would be due to excess gas. But scientists have measured gas content in those who have bloating and distension, and people with these symptoms do not have more gas than people without symptoms.

How long do I need to take my antidepressant?

DEAR DOCTOR K: I've been on an SSRI antidepressant for a few months, and it has really helped improve my depression. How long do I need to take this medication?

DEAR READER: If you're fortunate enough to find an antidepressant that lifts your dark mood, and you aren't too troubled by its side effects, your doctor likely will renew the prescription indefinitely. As long as you continue taking the medication, you are unlikely to suffer a relapse of your depression. But perhaps you're having bothersome side effects. Selective serotonin reuptake inhibitor (SSRI) drugs, like fluoxetine (Prozac) or sertraline (Zoloft), sometimes cause side effects.

Surprising number of conditions cause vitamin B12 deficiency

DEAR READERS: In yesterday's column I began to answer a reader's question about the different causes of vitamin B12 deficiency, and whether to treat them with shots or pills. Today, we continue a discussion of the many conditions that can interfere with the ability of the small intestine (the part called the ileum) to absorb vitamin B12 from the foods you eat. As we get older, some people have more trouble absorbing the vitamin B12 in their food during digestion. Vitamin B12 in food is like leaves on a tree: It needs to be shaken loose. Stomach acid (and another stomach chemical called pepsin) are what shake vitamin B12 loose from food, allowing it to be absorbed by the ileum.

Can I take a supplement for my vitamin B12 deficiency?

DEAR DOCTOR K: I was recently diagnosed with a vitamin B12 deficiency. Can I take B12 supplements by mouth? Or do I need the shots?

DEAR READER: Tissues throughout the body need vitamin B12, especially in the brain, spinal cord and bone marrow, where blood cells are made. Vitamin B12 in the diet gets absorbed in the part of the small intestine called the ileum. There, it enters the blood. Vitamin B12 deficiency can cause anemia, and problems with the bones, brain and spinal cord. Low vitamin B12 levels in the blood basically have two causes: Either there is not enough B12 in the diet, or the B12 in the diet has trouble getting absorbed by the ileum. B12 is found naturally only in animal products like meat, fish, poultry, eggs and milk. Many cereals are fortified with it.

I’m seeing my doctor for frequent headaches. What is likely to happen at the appointment?

DEAR DOCTOR K: I've made an appointment to see a doctor because of my frequent headaches. What is likely to happen at the appointment?

DEAR READER: If your headaches are severe, occur often, or are unresponsive to nonprescription pain relievers, it makes sense to see your doctor. He or she will try to determine the causes of your headaches and design a treatment plan. Your appointment is likely to begin with a series of questions about your headaches.

What is a patient-centered medical home?

DEAR DOCTOR K: I've been going to a family medicine practice for years. My doctor just told me the practice is going to become a "patient-centered medical home." What does that mean? How is this going to affect my health care?

DEAR READER: Many family medicine practices across the country are switching to a team-based model of care called a patient-centered medical home (PCMH). The PCMH turns a doctor's practice into a physician-led team. This team will develop a long-term treatment plan for you that focuses on prevention. Basically, the PCMH was born out of the realization that 21st-century medical care has become more complicated.

Should I read with my toddler every day?

DEAR DOCTOR K: My pediatrician has urged me to read with my toddler every day. Why? And where do I begin?

DEAR READER: Reading with children at a young age helps them develop their reading skills and language. A child who reads with his or her parents will learn to enjoy books, learn to read faster and want to read more. But reading to a baby is more than that. It's also a bonding experience. Even though the baby can't really understand, he or she will begin to connect spoken words to the words printed on a page. The baby will enjoy the sound of your voice and start to develop listening skills. And the book will have pictures that awaken the baby's curiosity.

How can I reduce the risk of side effects of new medications?

DEAR DOCTOR K: I need to start taking a new medication to treat a recently diagnosed condition. Is there anything I can do to reduce the risk of side effects?

DEAR READER: My colleague Dr. Gordon Schiff, associate professor of medicine at Harvard Medical School, says it well: "All drugs have effects -- the ones we want and the ones we don't. The unwanted effects are known as side effects." When you take a drug, it is distributed throughout your body, to all your organs and tissues. The drug may do different things in those different organs.