Also referred to as pyridoxine, pyridoxamine, and pyridoxal, vitamin B-6 is involved in the metabolism of amino acids, glucose, and lipids in the liver. Vitamin B-6 is also crucial in the synthesis of neurotransmitters, hemoglobin, and histamine, as well as proper gene expression. Because vitamin B-6 plays a significant role in more than 100 metabolic reactions, consuming enough of it on a daily basis is important. However, research regarding vitamin B-6 supplements is generally inconclusive, so those deficient in the vitamin should consider making dietary adjustments rather than taking supplements.
The amount of vitamin B-6 to be consumed on a daily basis depends upon an individual’s age and gender. The Food and Drug Administration has established the following Recommended Dietary Intake (RDI) of vitamin B-6:
- 0.5 milligrams per day for children 1-3 years
- 0.6 mg/day for children 4-8 years
- 1 mg/day for children 9-13 years
- 1.2 mg/day for females 14-18 years; 1.3 mg/day for males 14-18 years
- 1.3 milligrams/day for adults 19-50 years
- 1.5 mg/day for females over 50 years; 1.7 mg/day for men over 50 years
Although it is relatively rare, vitamin B-6 deficiency can have harmful effects. Dialysis, arthritis, liver disease, ulcerative colitis, Crohn’s Disease, and HIV patients are at higher risk for vitamin B-6 deficiency, as well as individuals coping with alcoholism and those who take certain medications like penicillamine and hydrocortisone. It has also been found that oral contraceptives and other estrogens can interfere with vitamin B-6 metabolism, resulting in deficiency. Those deficient in the vitamin might consider changing their diets in order to ensure that they are consuming enough of the nutrient from food.
There are lots of great sources of vitamin B-6 in a wide range of delicious foods. Vitamin B-6 is found in meat, poultry, fish, eggs, whole grains, legumes (bean and peas), potatoes, yeast, bananas, corn, cabbage, yams, prunes, watermelon, and avocado. One’s daily quota of vitamin B-6 can be easily consumed through food, including these vitamin B-6 rich food sources:
Banana, medium size
Chicken breast, 3 oz., roasted
Pork loin, 3 oz., roasted
Baked potato with skin, 3 oz.
Watermelon, 1 cup
Black beans, boiled, 1 cup
For more information about nutrition, check out the Optimal Nutrition section of the Go Ask Alice! archives. If you’re a Columbia student on the Morningside campus, you can make an appointment with a Registered Dietitian to discuss your intake of vitamin B-6. If you are on the Medical Center campus, contact Medical Services to make an appointment with a Registered Dietitian. While you’re at it, take a look at Columbia’s Get Balanced Guide for Healthier Eating for more information and ideas.
Dear Udderly confused,
The major difference between soymilk and "regular" milk (predominantly cow's milk in the United States; goat and sheep's milk are other options) is that one is derived from a plant and the other from an animal. Although ethical, hypothetical, or debatable issues frequently arise when discussing this subject, this answer is going to deal strictly with the nutritional differences between these two kinds of milk.
What's most commonly referred to as simply “milk” is cow's milk, a product of the cow’s mammary gland. As with all other animal-based foods, it's a complete protein; that is, it supplies people with all the necessary amino acids to form proteins. Cow's milk contains 8 grams of protein and 12 grams of carbohydrates per 8-ounce cup. Cow's milk is a rich source of other nutrients as well. One cup provides adults with about 30 percent of their daily calcium needs and about 50 percent of their vitamin B12 and riboflavin requirements. Often, milk is fortified with vitamin D to facilitate the absorption of calcium. Vitamin A is usually added to milk as well. Depending on the selection, cow's milk can have a significant amount of fat. (See the chart at the end of the answer for a comparison of the fat content of some varieties of milk.)
Lactose, the primary carbohydrate in cow's milk, poses a digestive problem for some people. These folks are deficient in the lactase enzyme that's needed to break down this milk sugar, causing gas, bloating, and diarrhea after consuming some forms of dairy products. The solution is to purchase products with the lactose already broken down, to take the enzyme in the form of a pill or drops, or to find a substitute for these foods. Check out Lactose intolerance for more information.
Soymilk is not technically milk, but a beverage made from soybeans. It is the liquid that remains after soybeans are soaked, finely ground, and then strained. Since it doesn't contain any lactose, soymilk is suitable for lactose intolerant folks. It's also a popular cow's milk substitute for vegans and vegetarians since it's based on a plant source (others include rice, oat, almond, coconut, and potato milk).
One cup of unfortified soymilk contains almost 7 grams of protein, 4 grams of carbohydrate, 4½ grams of fat, and no cholesterol. Although soymilk supplies some B vitamins, it's not a good source of B12, nor does it provide a significant amount of calcium. Since many people substitute soy beverages for cow's milk, manufacturers offer fortified versions. These varieties may include calcium and vitamins E, B12, and D, among other nutrients. If you do choose to use soymilk instead of cow’s milk, read labels carefully to be sure you're getting enough of these important nutrients or consider getting them from alternative food sources.
Soymilk may help some people reduce their risk for heart disease. Soy naturally contains isoflavones, plant chemicals that help lower LDL ("bad" cholesterol) if taken as part of a "heart healthy" eating plan. The recommendation is to take in about 25 grams of soy protein per day. One cup of soymilk has about 7 - 10 grams of protein, depending on the brand. Previously, researchers thought soy consumption was correlated with increased rates of breast cancer, but recent research suggests that soymilk consumption may actually reduce breast cancer rates for some populations, including post-menopausal women and Asian populations. Soy’s unique effect on Asian women is thought to be the result of larger amounts of dietary soy consumed over longer periods of time than other in women.
All in all, what you choose to drink is really a matter of personal preference and your health objectives. You may find this chart helpful in comparing the nutritional qualities between cow's milk and soymilk [per 1 cup (8 oz.) serving]:
|Reduced fat (2%)||120||5||38||297||.89|
|Low fat (1%)||100||3||27||300||.90|
*RDA (men and women) for: Calcium: 1,000 - 1,300 milligrams/day (depending upon age) Vitamin B12: 2.0 micrograms/day
May you always have a tall glass of (soy or cow's) milk with your cookies!
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Yes, there certainly are! Good sources include:
- Canola and olive oils.
- Ground flaxseed.
- Leafy green veggies.
There are three main types of omega-3s. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are mainly found in fish, whereas alpha-linolenic acid (ALA) is found elsewhere. Good sources of ALA include vegetable oils (such as soybean or canola), nuts (especially walnuts), flax seeds and flaxseed oil, and leafy vegetables (like kale, spinach, and Brussels sprouts). You could try adding some walnuts and flaxseed into your oatmeal, yogurt, or smoothie, and use vegetable oil for cooking or in a salad dressing to top off a leafy veggie. Try using canola oil to make a vegetable stir fry with tofu. Tahini, which is made with sesame seeds, is a great source of omega-3s and can be used to make sauces and dips, such as hummus. For more information about nutrition, check out the Get Balanced Guide to Healthier Eating as well as the Alice! Health Promotion Nutrition Initiatives.
Omega-3s fatty acids are polyunsaturated fatty acids that your body needs for numerous body functions, such as controlling blood clotting and normal brain function. Omega-3s have been shown to help prevent heart disease and possibly stroke, may help control lupus, eczema, and rheumatoid arthritis due to anti-inflammatory properties, and could be protective against certain types of cancer and other conditions.
There is some debate on whether sources of ALA carry the same benefits as fish sources of EPA and DHA. The body converts ALA into EPA and DHA, but not everyone’s body does this well. If you’re not averse to making an exception to your vegetarianism for fish oil, you can consider taking a fish oil supplement and might want to speak with your health provider or a nutritionist before doing so. For questions about your specific individual nutritional needs, Columbia students can make an appointment with Medical Services on the Morningside Campus or Student Health at the Medical Center to speak with a healthcare provider or nutritionist.
These claims are questionable at best. Here's the scoop: HCA — short for hydroxy citric acid — is an ingredient found in many weight loss supplements. It's derived primarily from the Garcinia cambogia plant. Citric acid is a substance involved in the metabolism of carbohydrates. HCA (a modified form of citric acid) is believed by some to inhibit the enzyme that allows carbohydrates to be stored as fat. It is suggested that, in the presence of HCA, excess carbohydrates would be expended instead of being stored as fat. A decrease in appetite is purported to be a side effect of this process, which further promotes weight loss. This certainly sounds good in theory. But... in 2009, a popular brand of dietary supplements for weight loss containing HCA as the main active ingredient was recalled after the U.S. Food and Drug Administration (FDA) issued a safety warning. The FDA received 23 reports of liver problems among those who took them, as well as other problems such as seizures and cardiovascular problems, and one death occurred. Since then the makers of the brand have stopped using HCA in their formulas, but HCA remains the active ingredient in several weight loss supplements that are currently available.
Studies on the effectiveness of HCA in animals and humans indicate mixed results. A study using rats found that high daily doses of HCA led to testicular atrophy and other toxicities, while other studies using smaller doses of HCA have found no adverse effects in lab animals. In human trials, there are studies that have found HCA as an effective weight loss supplement, while other studies have found that HCA does not prevent fat storage or promote weight loss.
Although some web sites claim HCA is safe, the truth is, we really don't know. Considering the 2009 recall of products containing HCA and the lack of information on long-term effects, is HCA worth the possible risks associated with it?
You may want to consider speaking with a health care provider to develop an effective weight loss plan. If you are a Columbia student on the Morningside campus, you can make an appointment with a health care provider and/or nutritionist by calling 212-854-2284 or logging on to Open Communicator. If you are on the Medical Center campus, you can do the same by calling 212-305-3400 or logging on to the Student Health Service web portal. You can also check out the Get Balanced! and CU Move initiatives, to help you reach your nutrition and physical activity goals.
Dear Just wondering,
Dolomite, or calcium magnesium carbonate, is a common mineral extract that occurs as crystals in large rock beds of limestone. Calcium carbonate is a cheap calcium supplement with a high percentage of calcium by weight, but the body has difficulty in breaking it down for use. Though dolomite in powdered form is soluble in weak acids, stomach acid doesn’t do the best job of dissolving it, especially in people with decreased stomach acid secretions (e.g., sick and elderly people). Other forms of calcium like calcium citrate are easier for the body to absorb.
In addition to being a less effective source of calcium, dolomite may be hazardous to your health. Dolomite deposits also contain other elements such as barium, lead, and iron and manganese carbonates as impurities. In the early 1980s, concern arose regarding heavy-metal contamination of calcium supplements when a study found high concentrations of lead in dolomite supplements. Since it may contain the toxic elements mercury and lead, dolomite is not a recommended source for calcium and magnesium — other forms of these minerals are available that would be safer to take.
See Iron, calcium, and constipation, oh my! for more info about calcium supplements. If you have questions about your individual nutritional needs or want more advice on nutritional supplements, talk with a health care provider or nutritionist. Students at Columbia on the Morningside campus can make an appointment with a nutritionist by calling 212-854-2284 or logging on to Open Communicator. If you are on the Medical Center campus, you can reach out to the Center for Student Wellness and the Student Health Service.
You can add citrus fruits such as lemons, oranges, and grapefruits to your list of pectin-rich foods. Strawberries and other fruits and vegetables also contain some pectin, but not as much as apples and fruits in the citrus family. Pectin is also added to certain foods, such as jams/jellies, because it acts as a thickening agent since it becomes gel-like when dissolved in water.
Pectin is a water-soluble dietary fiber. It can be found in most plants. Pectin slows the passage of food through the intestine and helps to lower blood cholesterol levels. In the intestine, it's believed that pectin fibers bind to bile (produced by the liver from cholesterol), which is then excreted from the body. Evidence supports the use of pectin for treating diarrhea, while studies are also being conducted to determine pectin’s potential benefits for preventing and treating certain types of cancer.
For additional information on fiber, check out the Related Q&As below.
It might be a good idea to seek further guidance from a nutritionist. If you are a Columbia student on the Morningside campus, you can make an appointment with a nutritionist by calling 212-854-2284 or logging on to Open Communicator. If you are on the Medical Center campus, you can reach out to the Center for Student Wellness or Student Health.
Dear Ginkgo User,
In fact, there’s currently no research to suggest any connection between taking ginkgo and increased blood pressure. You said that the change in your blood pressure is recent? If so, it’s recommended you speak to your primary care provider — quick changes in health markers such as blood pressure could indicate an underlying problem. It is possible that other factors may have contributed to this situation. Columbia students on the Morningside campus can make an appointment with Medical Services using Open Communicator. Columbia students at the Medical Center can make an appointment at Student Health.
In terms of the research on ginkgo and blood pressure, most has been related to whether or not ginkgo is effective at lowering blood pressure. This, too, has proved inconclusive. You mention that ginkgo is working as a memory enhancement tool for you. That’s great! Just make sure that your primary care provider, in addition to any other health care professional you see, knows all of the medications (this includes supplements) you take.
More research needs to be done on memory enhancement and ginkgo. There has been some research that indicates improvements in blood flow to the brain, thus enhancing memory in people who suffered impairment; but, there is no proof that ginkgo will improve memory in people who have not had an impairment. Unless you have had a decrease in memory due to an impairment of blood flow, ginkgo has not been proven to increase memory. Since ginkgo can be expensive (around $30 for a bottle of 60 capsules) it may not be the best (or least expensive) option for some people.
Dear Curious Carrot,
Beta-carotene has become an increasingly popular topic in the field of nutrition. High in antioxidants, beta-carotene is a nutrient found in foods like carrots, spinach, and kale. Recent studies have revealed possible links between adequate beta-carotene intake and slower progression of diseases like Age-Related Macular Degeneration and various types of cancer. However, excessive beta-carotene consumption has not been shown to fully prevent these diseases, and too much of it can actually be very harmful.
In the case of Age-Related Macular Degeneration, a study published in the Journal of the American Medical Association found an inverse association between above-average intake of beta-carotene (up to 13 times the average amount) and the development and progression of macular degeneration among the elderly. However, the 35% reduced risk demonstrated by this study cannot be attributed exclusively to beta-carotene, because other nutrients, including zinc and vitamins C and E, were consumed in excessive amounts as well.
In a different study, beta-carotene supplements taken along with increased Vitamin E, selenium, and zinc over a period of seven years was associated with lower total cancer incidence and all-cause mortality in men. Because many men are deficient in beta-carotene, they may benefit significantly from increased beta-carotene consumption (enough to bring them to what is referred to as a “baseline,” or average level). However, for women, many of whom do not experience natural beta-carotene deficiency due to their unique set of hormones and lipid and nutrient transport methods, supplementation had no measurable benefits. Further, the same study demonstrated that increased beta-carotene consumption in individuals experiencing the initial phases of cancer development was actually harmful.
A 2010 study published in the Journal of Nutrition demonstrates that although it is often said that natural sources of beta-carotene from fruits and vegetables are more easily absorbed by the body, foods and supplements fortified with beta-carotene and Vitamin A are not harmful to the average person when consumed in moderate quantities (approximately seven milligrams per day). However, the study notes that beta-carotene levels and intake requirements are highly variable, so it is difficult to make blanket statements about recommended daily intake.
A more recent study from March 2012 reported that above-average beta-carotene consumption does not prevent skin cancer and adenoma recurrence, lung cancer, or total cancer. In fact, the study cites a separate clinical experiment called the Beta-Carotene and Retinol Efficiency Trial, in which it was proven that lung cancer was 39% more likely among individuals who consumed high levels of beta-carotene and either smoked or were previously exposed to asbestos. At best, a U.S. Preventive Services Task Force (USPSTF) study found that beta-carotene had no effect on cancer or cardiovascular disease development among older adults, and that overall cancer development was actually facilitated by excessive beta-carotene consumption among heavy smokers. Therefore, the USPSTF does not recommend beta-carotene supplements, and reinforces that no supplements can take the place of a healthy diet. Indeed, there is no evidence that beta-carotene from natural food sources is harmful to smokers or any other population.
If you’re a Columbia student and you have more questions about beta-carotene or any other nutrient, you can make an appointment with a health care provider or registered dietician at Medical Services on the Morningside campus, or with Student Health at the Medical Center campus. In the meantime, for more information about nutrition, check out Columbia’s Get Balanced Guide for Healthier Eating, the other Get Balanced nutrition resources, as well as the related questions linked below.