What Fruits Should You Eat at Night to Lose Weight?

If you're trying to lose weight and like to snack at night, you can’t go wrong with a healthy helping of whole fruit. Not only is fruit low in calories, but its natural sweetness may help satisfy your after-dinner sweet tooth. Any fruit makes a good choice; the trick is to mind your portions and keep your overall calories in check.

Snack Calories

There's nothing wrong with snacking at night. The problem is late-night snackers tend to eat more overall calories, according to Beth Israel Deaconess Medical Center, and this may lead to weight gain. Even eating too many fruit calories can cause you to gain weight. So you first need to know and track your daily calorie needs for weight loss, which typically ranges from 1,200 to 1,800 calories a day depending on your gender and activity level, and saving about 200 calories for your nighttime fruit snack.

Go Large With Melons

If you're looking for a large nighttime snack that won't overdo it on calories, go for melons such as watermelon, cantaloupe or honeydew. These water-rich fruits are very low in calories, which means you can eat a lot and still stay within your 200-calorie snack limit. You can enjoy 3 cups of honeydew or cantaloupe balls for just under 200 calories. Or, even more filling, have 4 cups of watermelon balls for 184 calories.

Sweet Berries

Berries also make a good nighttime snack choice. They're not only low in calories but also filled with fiber and antioxidants. Indulge on 4 cups of sliced strawberries for 196 calories. Raspberries are also a good choice with 192 calories in a 3-cup serving. Raspberries are very high in fiber, however, with 24 grams in that same 3-cup serving, and if you're not used to eating that much fiber, you might experience abdominal discomfort. So go slow starting with 1 cup at a time, and be sure to drink plenty of water.

Apples and Pears

Apples and pears also make good nighttime snack options when trying to lose weight. There's no need for any special preparation, and the crunch of the skin and meat of the fruit can make it a very satisfying choice. One medium apple or pear has about 100 calories. You can add 1 ounce of low-fat cheddar cheese to your apple or pear snack if you enjoy the balance of sweet and savory for an additional 100 calories.

Caffeine And Healthy Diet May Boost Memory, Thinking Skills

A study published in this month’s Journal of Nutrition is any indication, the caffeine in coffee might offer not just a momentary mental boost but also longer-term effects on thinking skills. Having an alcoholic drink a day might also benefit our mental performance, but the line between just right and too much is uncertain. An even better strategy for maintaining memory and thinking skills with age may be to eat a healthy diet.

In the study, researchers from the National Institute on Aging compared scores on various tests of thinking skills and memory with caffeine, alcohol, and nutrient intake in 727 men and women taking part in the Baltimore Longitudinal Study of Aging. Over all, participants who ranked high on the healthy diet scale did better on 10 tests of memory than those with lower diet scores. The same held true for those who took in more caffeine. The effects for moderate alcohol drinking were mixed.

The caffeine-brain connection

The reason you get a quick wakeup call after chugging a mug of coffee has to do with the way caffeine tricks your brain. Not only is caffeine a brain stimulant, but it also blocks receptors for a chemical called adenosine, which normally prevents the release of excitatory brain chemicals. With adenosine out of the way, these brain-sparking chemicals can flow more freely—giving you a surge of energy and potentially improving mental performance and slowing age-related mental decline.

The Journal of Nutrition study isn’t the last word on the subject of caffeine and memory. It showed that people—particularly those who were ages 70 and over—who took in more caffeine scored better on tests of mental function, but not on memory tests or other measures of mental ability.

Some previous studies have shown improved long-term memory performance and thinking ability in regular caffeine consumers; others haven’t shown any connection.

Drink to your cognitive health?

When it comes to alcohol, its effects on memory and thinking skills may depend on how they are measured and how much you’re drinking. In this study, moderate alcohol use appeared to improve working memory and attention—especially in women and in those ages 70 and over. But those benefits could come at the expense of declines in skills like executive function and global thinking.

Excessive drinking, defined as more than two drinks a day for men or more than one a day for women, is known to harm the brain. Over time, excessive drinking can cause everything from short-term memory lapses to more permanent problems. Any benefits from alcohol seen in theJournal of Nutrition study came from moderate drinking.

Better memory through diet

The study also looked at the connection between diet and mental performance. People who ate foods with plenty of healthful nutrients had better attention and memory than participant with poorer diets. A healthy diet was also linked to good thinking skills in women and participants under age 70. In particular, foods that are part of the Mediterranean diet—fruits, vegetables, nuts, fish, olive oil, and whole grains—show promise for preserving memory and preventing Alzheimer’s and other forms of dementia.

A recipe for maintaining memory

This study is just one of many linking healthy eating habits with maintaining memory and thinking skills into old age. Continuing a healthy diet, or switching to one, makes sense on many levels. It probably is good for your brain, and it’s definitely good for your heart, bones, muscles, and overall health.

As for caffeine? There’s no evidence yet that you need to start drinking coffee or tea to protect your brain. If you like drinking caffeinated beverages, enjoy them. But keep in mind that adding lots of sugar or cream, or getting caffeine via sugar-sweetened soda, may counter any benefits.

What about alcohol? If you enjoy drinking alcohol, keep it moderate—or less. As the researchers write, “alcohol has potentially deleterious effects over time with lower intake being a better choice than moderate intake.”

Antioxidants: What You Need to Know

What are antioxidants?

The cells in your body are exposed to oxygen every day. Oxygen is important for your body’s health, but exposure to oxygen also causes oxidation. In oxidation, body chemicals are altered and become what are known as free radicals. Exposure to environmental factors, such as sun exposure, cigarette smoke, alcohol and pollution, also creates free radicals.

Over time, free radicals can cause a chain reaction in your body that damages important body chemicals, DNA and parts of your cells. Some cells can heal, while others are permanently damaged. Scientists believe free radicals may contribute to the aging process as well as diseases like cancer, diabetes and heart disease.

Antioxidants are natural substances that may stop or limit the damage caused by free radicals. Your body uses antioxidants to stabilize the free radicals. This keeps them from causing damage to other cells. Antioxidants can protect and reverse the damage caused by oxidation to some extent.

Where are antioxidants found?

Your body produces some antioxidants to fight off the free radicals formed by normal body processes. Your body can also get antioxidants by eating a healthy diet. Examples of antioxidant-rich foods include fruits and vegetables that are high in nutrients such as vitamins A, C and E, beta-carotene, lutein, lycopene and selenium.

What foods are good sources of antioxidants?

To get the most antioxidants, eat a diet that includes a healthy mix of colorful fruits and vegetables and other antioxidant-rich foods:

• Vitamin A is found in milk, liver, butter and eggs.
• Vitamin C is found in most fruits and vegetables. Those with the highest amounts of vitamin C include papayas, strawberries, oranges, cantaloupe and kiwi, as well as bell peppers, broccoli, Brussels sprouts, tomatoes, cauliflower and kale.
• Vitamin E is found in some nuts and seeds, including almonds, sunflower seeds, hazelnuts and peanuts. It can also be found in green leafy vegetables, such as spinach and kale, and in oils, such as soybean, sunflower, corn and canola oils.
• Beta-carotene is found in colorful fruits and vegetables, including carrots, peas, cantaloupe, apricots, papayas, mangoes, peaches, pumpkin, apricots, broccoli, sweet potatoes and squash. It can also be found in some leafy green vegetables, including beet greens, spinach and kale.
• Lutein is found in green leafy vegetables, such as spinach, collards and kale, broccoli, corn, peas, papayas and oranges.
• Lycopene is found in pink and red fruits and vegetables, such as pink grapefruit, watermelon, apricots and tomatoes.
• Selenium is found in cereals (corn, wheat and rice), nuts, legumes, animal products (beef, fish, turkey, chicken, eggs and cheese), bread and pasta.

While foods that are rich in vitamin E and beta-carotene are very healthy and help reduce cancer risk, the U.S. Preventive Services Task Force and the American Academy of Family Physicians recommend against taking vitamin E or beta-carotene supplements for the prevention of cancer. People who smoke or have a high risk for lung cancer should not take supplemental beta-carotene because it can increase the risk of lung cancer.

The best way to get antioxidants is by eating a diet with lots of vegetables, fruits, whole grains, seeds and nuts. Variety is also important.

How to create a balanced meal

The carbohydrates, fats and proteins in the foods we eat provide our bodies with energy to fuel our physical activity and digestion, as well as powering our energy-hungry brains.

While our bodies can derive energy from all three of these food components, consuming each in the proper proportion will help you achieve balanced nutrition, maintain energy levels throughout the day, and contribute to longer-lasting satiety.
Below are the categories for each food group:

VEGETABLES AND FRUITS
Half of each major meal you consume should be vegetables or fruits. Because fresh fruits and vegetables are high in both water and fiber, and low in fat, these foods are typically low in overall calories. Thus, meals that are composed primarily of vegetables and/or fruits can help you control your total calorie intake. Also, fruits and vegetables provide high concentrations of vitamins, minerals and antioxidants, compounds that facilitate cellular repair, can help to prevent cancer and maintain overall health. Particular group of nutrients are associated with each vegetable or fruit color group. For example, dark leafy greens are typically high in both iron and folic acid, while orange and yellow fruits and vegetables often contain potassium and vitamin C. Thus, by consuming a wide range of colors, you are more likely to achieve optimal levels of each vitamin and mineral.

GRAINS AND FIBER
A quarter of your main meals should be comprised of grains, but these come in a number of forms, so you’ll have to be an attentive shopper to be sure you choose ones that give you nutritional benefit. There are two kinds of carbohydrates we’ll discuss here. The first is refined, or “simple”, carbohydrates, which means the sugars are broken down and therefore are much more quickly absorbed by your body. Simple sugars can lead to blood sugar spikes right after the meal, and these levels can then quickly fall after your body stores or uses the energy from the sugars you consume. Sugar is one form of energy for your body, and so when your blood sugar goes up, you’ll typically feel energized…aka a “sugar high”. But, when it falls quickly, you can be left feeling tired, and craving the high level again, which can propagate a vicious cycle of consuming more food and more calories to re-achieve that sensation. Steady levels of sugar in your blood are much more desirable, they can help reduce overeating and help you avoid the roller coaster feelings associated with oscillating high-then-low blood sugars.

Complex carbohydrates are the second type of carbohydrate we will discuss and are consumed in a less broken-down form. Therefore, it takes your body longer to digest them, keeping your blood sugar levels more level, and leaving you feeling fuller for a longer period of time. There is a standardized scale, called the “glycemic index” which rates foods on the degree of blood sugar elevation a person experiences after consuming certain foods. Using this scale may help you to choose foods that keep your blood sugar levels more steady.

Fiber is another component you can add to your diet and has many health benefit including helping you feel full and slowing sugar absorpt

PROTEIN
The keys to optimal protein consumption are quality and moderation. Most North Americans consume more than the recommended daily allowance (RDA) for protein. Rich sources of protein include meats, soy, legumes and nuts. However, it is important to bear in mind that many other foods in the diet, including grains and dairy, also contain protein, and thus contribute to overall protein intake. In selecting high quality meats, look for unprocessed meats and limit those meats that are high in saturated fat. (i.e. beef, lamb and pork other than tenderloin). A good rule of thumb for meat-eaters is to limit meat intake to one serving per day (or two small servings).

Some proteins such as salmon, nuts such as walnuts, pecans and hazelnuts, along with some oils such as flaxseed oil are loaded with Omega-3 fats. Intake of these fats have been suggested to decrease heart disease and stroke risk.1 The data is mixed on whether Omega-3 fat intake can help decrease the risk of cancer, with the most convincing data revolving around breast cancer reduction, according to the American Cancer Society.2 In order to enjoy the benefits of omega-3 fatty acids, consider incorporating regular consumption of fish into your diet.

FATS
Appropriate levels of healthy fats in the diet are important for many reasons. Our bodies use fats in many ways. The membranes of all the cells in our bodies are made of fats, a layer of fat under of skin keeps us warm, and, fat stores provide energy when supplies of glucose run out. As with protein, quality and moderation are crucial. In addition, fats called “trans fats” and are added to extend the shelf life of processed foods.

Consumption of these fats may increase your “bad” or LDL cholesterol, and lower your “good” or HDL cholesterol. Avoiding this sort of fat as much as possible will have heart-protective qualities. Look for unprocessed oils (such as extra virgin olive oil), and steer clear of processed foods in order to avoid trans fats as much as possible.

BEVERAGES
Water, and unsweetened tea and coffee are better choices than sweetened beverages. Teas can include herbal infusions, which offer caffeine-free options. Many sweetened beverages contain high fructose corn syrup, which is a simple carbohydrate, and, as above, can lead to blood sugar spikes, adds extra calories and typically won’t keep you feeling full for too long.

If you follow the basics of creating this healthy plate, you'll be on your way to feeling your best and obtaining optimal health! Stay tuned for more articles on healthy eating and tips to help you make good dietary choices!

Foods That Are High in B Vitamins

The B vitamins include thiamin, riboflavin, niacin, folate (also called folic acid or folacin), vitamin B6, vitamin B12, biotin and pantothenic acid. The B vitamins work collectively and individually in every cell to perform many different jobs, including helping the body release the energy it gets from carbohydrates, proteins and fats.

Some foods are especially good sources of just one B vitamin, while other foods contain several B vitamins. Luckily, B vitamins are widely distributed throughout the food supply, so if you're eating a varied, balanced diet that includes foods from all food groups, you’re most likely getting as many vitamins as you need.

Thiamin

Your body relies on thiamin to regulate your appetite and support your metabolism. Some of the best sources of thiamin are pork, ham, dark green leafy vegetables, fortified whole-grain cereals and baked goods, wheat germ, enriched rice, green pea, lentils and nuts such as almonds and pecans. Women and men need 1.1 and 1.2 milligrams daily, respectively.

Riboflavin

Consume riboflavin for healthy skin. Milk and milk products such as yogurt and cheese are rich in riboflavin. Asparagus, spinach and other dark green leafy vegetables, chicken, fish, eggs and fortified cereals also supply significant amounts of riboflavin to the diet. Aim for an intake of 1.1 milligrams for women and 1.3 milligrams for men.

Niacin

Chicken, turkey, salmon and other fish including canned tuna packed in water are all excellent natural sources of niacin. Fortified cereals, legumes, peanuts, pasta and whole wheat also supply varying amounts. Niacin promotes healthy nerve function, benefits your cardiovascular system and aids in energy production. Men need 16 milligrams of niacin, while women need 14.

Folate

To remember which foods are high in folate, remember that the word folate has the same root as the word foliage. Leafy greens such as spinach and turnip greens and other fresh fruits and vegetables are all excellent sources of folate. All grain products such as breads, pastas and rice are fortified with folate. Consume 400 micrograms of folate daily. It promotes red blood cell health and nervous system function.

Vitamin B6

Some of the best sources of vitamin B6 are poultry, seafood, bananas, leafy green vegetables such as spinach, potatoes and fortified cereals. Your diet should include 1.3 milligrams of B-6 daily to support new red blood cell growth.

Vitamin B12

Animal foods are the only natural source of vitamin B12, but many products, including soy products and cereals, are fortified with B12 so it is widely available in the food supply. Other good natural sources include shellfish, such as clams, mussels and crab, fin fish and beef. You need only a small amount of B-12 -- 2.4 micrograms daily. This B-12 will boost red blood cell production and support your nervous system.

Biotin and Pantothenic Acid

Liver and egg yolks are the richest dietary sources of biotin -- a nutrient needed for a healthy metabolism -- but fortunately this B vitamin is well distributed throughout the food supply, so it is unlikely that anyone eating a balanced, varied diet will experience a deficiency. Salmon, pork and avocado are good sources; most fruits and vegetables contain a little biotin, as do cheeses and grain foods.

Yogurt and avocado are both excellent sources of pantothenic acid, a vitamin needed for enzyme function, but it is also available in a wide variety of foods such as legumes including lentils and split peas, sweet potatoes, mushrooms and broccoli. Consume 5 milligrams daily.

Supplements Can Increase Magnesium Levels

Magnesium is the eighth most abundant element on the earth's crust, and is found in every organ in the human body. The physician Joseph Black first recognized magnesium as an element in 1755, but even before Black's time, physicians were recommending the magnesium carbonate "magnesia alba" for people with an upset stomach.

Today, researchers know magnesium plays a part in more than 300 reactions in the body. Magnesium is necessary to synthesize proteins, DNA and RNA. It plays a role in our metabolism, and cells use magnesium to transport calcium and potassium ions across the cell walls. Healthy magnesium levels are key to nerve function, muscle contraction, heartbeat, and healthy bones. Yet all of the magnesium in the average person weighs only 0.8 ounces (25 grams).

Magnesium is still used as an antacid and a laxative today. As a supplement, magnesium is touted to prevent hearing loss, kidney stones and migraine headaches. Magnesium supplements are also claimed to improve athletic performance, and treat sleep troubles including restless leg syndrome and insomnia. Low magnesium levels have been linked to osteoporosis, anxiety, irritability, depression and attention deficit hyperactivity disorder (ADHD).

Doctors sometimes recommend magnesium supplements to treat people with high blood pressure, preeclampsia, eclampsia, heart attacks, premenstrual syndrome (PMS) irregular heartbeat, or an unhealthy ratio of HDL (high-density lipoprotein) cholesterol to LDL (low-density lipoprotein) cholesterol.

Some people with certain chronic conditions — including diabetes, multiple sclerosis, fibromyalgia, and chronic fatigue syndrome — use magnesium supplements to control symptoms. Magnesium is occasionally recommended to ease altitude sickness, hay fever, Lyme disease, asthma and chronic obstructive pulmonary disease (COPD). Magnesium applied directly to the skin is said to treat skin infections and speed up wound healing. Magnesium has also been touted to ease muscle cramps, sensitivity to loud noises and kidney stones.

Many Americans do not get enough magnesium, according to the National Institutes of Health. But some groups of people, who have certain diseases or conditions are even more likely to have low magnesium levels. Heavy drinking and alcoholism can result in chronically low magnesium levels, and gastrointestinal conditions such as Crohn's disease and celiac disease can also deplete magnesium levels.

Older adults tend to have lower magnesium levels than young adults. This happens, in part, because the gut becomes less efficient at absorbing magnesium and the kidneys become less efficient at retaining magnesium with age. Type 2 diabetes can cause the kidneys to excrete too much magnesium, and in turn lead to a magnesium deficit. And some medications, such as diuretics, the heart drug digoxin and penicillamine (used for rheumatoid arthritis) can all interfere with magnesium in the body.

Do magnesium supplements work?

Supplements can increase magnesium levels, especially those in the forms of magnesium aspartate, citrate, lactate and chloride. A 2011 study in the American Journal of Clinical Nutrition showed people who take magnesium supplements typically get more than the recommended daily amount.

The recommended daily intake of magnesium ranges from 320 milligrams to 420 milligrams, depending on age or gender.

In fact, a healthy diet can easily provide enough magnesium. Whole grains, nuts, fish, meat, dark green vegetables, legumes and many fruits contain significant amounts of magnesium.

Inadequate magnesium levels are not likely to cause symptoms, but a full-blown magnesium deficiency can cause nausea, fatigue and weakness. Severe magnesium deficiency may cause numbness, tingling, muscle contractions, seizures, abnormal heart rhythm and personality changes. People with very low magnesium levels, or hypomagnesemia, may suffer from involuntary eye movements.

Magnesium deficiency can sometimes cause coronary spasm, a phenomenon in which the arteries that supply blood to the heart spasm and block blood flow. Dangerously low levels of magnesium can also result in low calcium (hypocalcemia), and low potassium (hypokalemia) — which can be fatal in extreme cases. Severely low magnesium can also result in a heart attack, respiratory arrest and death.

While magnesium supplements can certainly treat a magnesium deficiency, studies also show getting more magnesium than the bare minimum may help certain conditions. Several long-term studies have found a correlation between high magnesium levels and a lower risk of heart disease, sudden cardiac death and ischemic heart disease, according to the National Institutes of Health's Office of Dietary Supplements. Magnesium may also help prevent stroke. An analysis of seven studies including more than 200,000 people found that an extra 100 milligrams of magnesium a day reduced a person's risk of stroke by 8 percent, according to a February 2012 review in the American Journal of Clinical Nutrition.

Studies show magnesium supplements may lower blood pressure, but only by a little bit. One analysis of more than 22 studies on magnesium and blood pressure found that magnesium supplements reduced blood pressure by 2 to 4 mmHg, according to an April 2012 paper published in the European Journal of Clinical Nutrition. However, high blood pressure can fall within a range of 20 mmHg: from 140/90 mmHg to 160/100 mmHg. In the study, people's drop in blood pressure was greater when they increased their magnesium by eating more fruits and vegetables, or taking more than 370 milligrams of magnesium a day. Recommended daily intake of magnesium range from 320 milligrams to 420 milligrams, depending on age or gender. But because a diet with more fruits and vegetable will also increase levels of other nutrients, it is difficult to measure the independent effect magnesium has on blood pressure.

There is also a relationship between low magnesium levels and type 2 diabetes, studies have found, but exactly how the two are linked is still unclear. Low magnesium levels may worsen insulin resistance, which leads to uncontrolled blood sugar. But insulin resistance may also lead to low magnesium. Both situations may also be true where diabetes leads to low magnesium, and in turn low magnesium worsens diabetes, according to the NIH. A small number of studies show getting more magnesium may increase bone mineral density in elderly women, but more research is needed to clarify magnesium's potential in preventing or treating osteoporosis.

Guidelines from the American Headache Society and the American Academy of Neurology say magnesium is "probably effective" for migraine prevention. (However the guidelines recommend the nutritional supplement butterbur over magnesium to prevent migraines.)

The National Library of Medicine and the NIH determined that magnesium may help people with chronic fatigue syndrome and pain from fibromyalgia. Scientific evidence also indicates that magnesium may help PMS, high cholesterol, kidney stones, hearing loss, asthma attacks and chronic obstructive pulmonary disease (COPD). There are not enough studies to determine whether magnesium supplements could help anxiety, ADHD, hay fever, Lyme disease or multiple sclerosis, according to the NIH. Studies are less promising on magnesium's ability to boost athletic performance.

Are magnesium supplements safe?

Magnesium is one of the seven major minerals that the body needs in relatively large amounts (Calcium, potassium, sodium, chloride, potassium and phosphorus are the others). But too much of one major mineral can lead to a deficiency in another, and excessive magnesium can in turn cause a deficiency in calcium. Few people overdose on minerals from food. However, it is possible to get too much magnesium from supplements or laxatives.

People with kidney problems are more likely to experience an overdose of magnesium. Symptoms of toxic magnesium levels can range from upset stomach and diarrhea, to more serious symptoms of vomiting, confusion, slowed heart rate and dangerously low blood pressure. Severe magnesium overdoses can lead to problems breathing, coma, irregular heartbeat and even death.

Magnesium supplements can interact with several drugs. Taking magnesium too close to a dose of some antibiotics, including ciprofloxacin and moxifloxacin, may interfere with how the body absorbs the medicine. Similarly, magnesium can interfere with some osteoporosis drugs if the doses are taken too close together. Magnesium can also interfere with some thyroid medications. Magnesium supplement can also used to reduce joint pain.

The Vitamins You Should or Shouldn't Be Taking

In the early 1900s, Americans consumed all of their nutrients by eating food. In 2007, vitamin supplement sales topped $23.7 billion in the United States, according to the American Dietetic Association. But consuming more vitamins does not necessarily add up to improved health. How do you know what vitamins you need to take, if any, and what amount is appropriate?

Find Out What You're Missing

After moving from Florida to New York and starting a night job, Heidi Smith felt like she was always running on empty. "For years I thought I was just a grumpy, low-energy person," Smith explained. "I wish I'd known sooner that I just lacked vitamin D."

Working at night limited her exposure to the UV rays that help the body synthesize vitamin D. "Plus," she admitted, "I was eating pretty badly." When therapy and antidepressants failed to do the trick, she visited her physician, who tested her vitamin D levels and discovered a severe deficiency -- one that dietary changes alone would not rectify. Since being treated for a vitamin D deficiency, Smith has seen huge improvements in her energy level, "as though a cloud has been lifted," she said.

Most health-care practitioners agree that whole, natural foods remain the optimum source of nutrients. If your diet is lousy or your body's ability to absorb vitamins is compromised, however, you may require supplements. Registered dietitian Lauren Schmitt recommends that populations at risk for not meeting their nutrient needs, such as elderly adults, pregnant women and children, consider a basic multi-vitamin supplement. Women who experience heavy menstrual bleeding, strict vegans and vegetarians, and anyone who consumes fewer than 1,600 calories daily or can't stick to a balanced diet may also require supplements.

Various medical conditions, such as chronic digestive diseases and food intolerances, also create a need for vitamin supplements. Though numerous natural health-care practitioners use blood tests that supposedly check your nutrient levels, the tests lack scientific validity. If your doctor suspects a vitamin deficiency, he will likely run standard health tests, such as checking your blood cell counts, glucose levels, electrolytes and organ function. He will also ask you questions about your diet and lifestyle. In other words, vitamin deficiencies are diagnosed based on the symptoms they present and confirmed by your doctor's assessment of your overall health and dietary habits.

Common Deficiencies

Though people's specific dietary needs vary, certain nutrients are commonly lacking in the typical American diet.

Even if you consume a relatively healthy diet, you may be missing particular nutrients. The vitamin supplement most people should consider taking is vitamin D, according to Luigi Gratton, clinical nutrition specialist at the UCLA Risk Factor Obesity Program—the nutrient that had such a powerful impact on Smith's life. “Most folks in North America are deficient,” Gratton explains. The U.S. Institute of Medicine of the National Academy of Sciences recommends 5 micrograms of Vitamin D daily for those under 50.

Vitamin D is essential for proper calcium absorption and healthy bones. It also enhances your immune system and, for severely deficient people like Smith, your moods. If you rarely spend time outside and do not consume vitamin D-fortified dairy products, fish and other seafood regularly, discuss your need for vitamin D supplementation with your doctor.

Deficiencies of other vitamins are uncommon in people who live in the United States. If you consume a strict vegetarian or vegan diet, or suffer from the autoimmune disorder known as pernicious anemia, you may lack vitamin B12. The nutrient is found mainly in animal-derived foods and plays a major role in brain function, blood cell production and fatigue prevention. If you have a disorder that causes nutrient malabsorption, such as celiac disease or Crohn's disease, you may have difficulty absorbing all nutrients, particularly if you fail to manage your disorder appropriately.

The American Dietetic Association recommends consuming more of the B vitamin folate -- or the synthetic form, folic acid -- if you are pregnant, nursing or may become pregnant. Prenatal vitamins generally contain sufficient amounts of folate, as do whole grains.

Mega Bad

Consuming plentiful amounts of nutrients from food sources rarely causes problems. Excessive intake of most any vitamin supplement, however, can lead to a broad range of side effects, some of which are serious.

Vitamin supplements have been linked to nausea, diarrhea, stomach cramping, reduced cognitive abilities, interactions with medications and even death. For example, taking excessive doses of vitamin A in supplement form causes hypervitaminosis A -- a condition characterized by liver abnormalities, reduced bone density and birth defects. Excessive intake of vitamin B12, though not associated with toxic effects, can interact with medications, such as certain antibiotics and diabetes medications. Schmitt also describes taking unnecessary supplements as “not good use of your hard-earned money.”

To prevent unwanted side effects, avoid vitamin supplements that contain mega amounts -- more than 100 percent of the recommended daily allowance -- of particular nutrients and those that promise miraculous benefits. By law, the standard RDA is always listed on product packaging. Find that fine print and read it before taking any new supplement.