During my annual physical examination, the doctor said my hemoglobin was a little low. He did not prescribe iron supplements, but advised that I eat more iron-rich foods. Which foods are the best sources?

Liver tops the list, and other meats, poultry and fish contribute important amounts. If you like and can afford them, oysters and clams are especially good sources.

Of the nonmeat contributors, dried beans are an excellent choice, and if you bake them with molasses the iron content will rise even higher. Other good vegetable sources include lima beans, baked potatoes, sweet potatoes and peas, as well as many dark green leafy varieties, among them spinach, beet greens and chard. Bananas, oranges and dried fruits contain some. And whole grains and enriched breads and cereals provide as much as 1/3 of total daily intake.

Remember that two factors affect the amount of iron absorbed from food. Iron exists in both a "heme" and a "nonheme" form. About 40 percent of the iron in meat, fish and poultry is heme iron, which the body uses more efficiently. The rest of the iron in those foods and all in non-meat foods is nonheme iron. Happily, eating meat, fish or poultry with foods containing nonheme iron improves the absorption of iron from those foods. Alternatively, ascorbic acid (vitamin C) has the same effect, a fact of particular importance to vegetarians who eat no animal flesh.

I have heard that eating too many carrots can turn one's skin a bright orange color. Is this a form of vitamin-D toxicity?

No. Hypercarotenemia, as it is called, does occur in individuals who consume an excess of carotene, the precursor of vitamin A found in fruits and vegetables. It has been estimated that a daily intake of a pound of carrots a day will cause the characteristic color change after several weeks. For anybody but Peter Rabbit that is a lot of carrots to munch down on a daily basis.

The problem is usually traced not to eating large amounts of carrots and other carotene-rich produce, but to consumption of great quantities of carotene-loaded vegetable juices made in the extractors sold in health-food stores.

The visible effect comes from excess amounts stored in the fatty tissue immediately below the skin. The yellow-orange color, though not especially attractive, gradually disappears when dietary carotene intake is reduced.

I had a baby 3 months ago and breast-feed her. I am considerably overweight and would like to diet. Will that affect my ability to breast-feed over the next few months?

There is no reason not to begin a gradual weight-loss program as long as you approach it sensibly. But you must plan menus carefully to provide enough of the nutrients essential for breast-milk production without drawing on your own body stores.

Your core diet should include a quart of low-fat or skim milk fortified with vitamins A and D, with low-fat yogurt and cheeses, especially hard cheeses, as alternates. You will also want to have 8 ounces of lean meat or fish, five servings of fruits and vegetables rich in vitamins A and C, and four of whole-grain or enriched breads and cereals. How much more you will be able to eat and still lose weight depends both on how much milk your baby consumes each day and on your level of physical activity.

Women are normally advised to gain enough weight to lay down fat stores to be called upon as a source of calories for lactation for about three months. It is expected that after that time women whose weight is normal will need to increase their calories in order to maintain their weight while continuing to nurse. In individuals such as yourself, it makes good sense to call upon surplus stores for a significantly longer period of time.

1987, Washington Post Writers Grou