What are the best vitamins and minerals for fighting colds and flus?
There’s been a lot of hype in recent years about this supplement or that supplement being able to prevent colds and flus or lessen their duration and severity, but how much is real and how much is hype? Here are the top choices for my cold and flu arsenal.
Vitamin C has been demonstrated to have a strong anti-viral effect. Orthomolecular.org states: “In high doses, vitamin C neutralizes free radicals, helps kill viruses, and strengthens the body’s immune system. Taking supplemental vitamin C routinely helps prevent viral infections.” It has been shown to be effective against both the swine and bird flu.
The recommended dosage on Orthomolecular.org is as follows:
For best results, take vitamin C in evenly divided doses during the waking hours. Continue taking vitamin C on this schedule until, Pauling says, you have loose stool (just short of diarrhea). After having loosened stool, reduce the vitamin C dosage reduce by about 25 per cent. If you have another loose stool, reduce the vitamin C again, but if the symptoms of the viral infection begin to return, increase the dosage. You will quickly learn how much vitamin C to take; even children can learn to do this. Continue until you are completely well. Vitamin C greatly shortens the severity and duration of viral illnesses.
The recommended daily allowance of vitamin C for adults is 60 mg/day for adults, but research suggests that this a minimum to prevent deficiency diseases such as scurvy, not promote optimal health. The Linus Pauling Institute offers a comprehensive overview of optimal vitamin C intakes for different ages and conditions. Their basic recommendation is as follows:
For healthy men and women, the Linus Pauling Institute recommends a vitamin C intake of at least 400 mg daily. Consuming at least five servings (2½ cups) of fruits and vegetables daily provides about 200 mg of vitamin C. Most multivitamin supplements provide 60 mg of vitamin C. To make sure you meet the Institute’s recommendation, supplemental vitamin C in two separate 250-mg doses taken in the morning and evening is recommended.
What are the best food sources of vitamin C?
www.health.gov provides the following information on vitamin C content of common foods.
|Food, Standard Amount|| |
Vitamin C (mg)
|Guava, raw, ½ cup|| |
|Red sweet pepper, raw, ½cup|| |
|Red sweet pepper, cooked, ½ cup|| |
|Kiwi fruit, 1 medium|| |
|Orange, raw, 1 medium|| |
|Orange juice, ¾ cup|| |
|Green pepper, sweet, raw, ½ cup|| |
|Green pepper, sweet, cooked, ½ cup|| |
|Grapefruit juice, ¾ cup|| |
|Vegetable juice cocktail, ¾ cup|| |
|Strawberries, raw, ½ cup|| |
|Brussels sprouts, cooked, ½ cup|| |
|Cantaloupe, ¼ medium|| |
|Papaya, raw, ¼ medium|| |
|Kohlrabi, cooked, ½ cup|| |
|Broccoli, raw, ½ cup|| |
|Edible pod peas, cooked, ½ cup|| |
|Broccoli, cooked, ½ cup|| |
|Sweetpotato, canned, ½ cup|| |
|Tomato juice, ¾ cup|| |
|Cauliflower, cooked, ½ cup|| |
|Pineapple, raw, ½ cup|| |
|Kale, cooked, ½ cup|| |
|Mango, ½ cup|| |
Did you know cholesterol acts as a building block for vitamin D in our bodies? The World’s Healthiest Foods website explains:
Cholesterol is the basic building block of vitamin D in humans….when ultraviolet light hits the cells of our skin, one form of cholesterol found in our skin cells-called 7-dehydrocholesterol-can be converted into cholecalciferol, a form of vitamin D3.
The best source of vitamin D is sun exposure, which of course is often difficult to come by in winter. In lieu of sunlight, food and supplements are your next best option. The RDA for vitamin D from the National Institute of Health is as follows:
|0–12 months*||400 IU |
|400 IU |
|1–13 years||600 IU |
|600 IU |
|14–18 years||600 IU |
|600 IU |
|600 IU |
|600 IU |
|19–50 years||600 IU |
|600 IU |
|600 IU |
|600 IU |
|51–70 years||600 IU |
|600 IU |
|over 70 years||800 IU |
|800 IU |
In 2010, the National Academy of Sciences set Tolerable Upper Intake Levels (ULs) for vitamin D as follows (source):
- infants, 0-6 months: 25 micrograms (1,000 IU) per day
- infants, 6-12 months: 38 micrograms (1,500 IU) per day
- children, 1-3 years: 63 micrograms (2,500 IU) per day
- children, 4-8 year: 75 micrograms (3,000 IU)per day
- children and adolescents, 9-18 years: 100 micrograms (4,000 IU) per day
- adults, 19 years and older: 100 micrograms (4,000 IU) per day
- pregnant and lactating women, 100 micrograms (4,000 IU) per day.
As you can see, there’s a pretty big difference in those numbers, and some individuals with chronically low levels may need additional supplementation. Studies have linked low vitamin D levels to increased risk of cold and flu.
What are the Best Food Sources of Vitamin D?
The National Institute of Health lists some of the top foods for vitamin D:
|Food||IUs per serving*||Percent DV**|
|Cod liver oil, 1 tablespoon||1,360||340|
|Salmon (sockeye), cooked, 3 ounces||447||112|
|Mackerel, cooked, 3 ounces||388||97|
|Tuna fish, canned in water, drained, 3 ounces||154||39|
|Orange juice fortified with vitamin D, 1 cup (check product labels, as amount of added vitamin D varies)||137||34|
|Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup||115–124||29–31|
|Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces (more heavily fortified yogurts provide more of the DV)||88||22|
|Margarine, fortified, 1 tablespoon||60||15|
|Liver, beef, cooked, 3.5 ounces||49||12|
|Sardines, canned in oil, drained, 2 sardines||46||12|
|Egg, 1 large (vitamin D is found in yolk)||41||10|
|Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75–1 cup (more heavily fortified cereals might provide more of the DV)||40||10|
|Cheese, Swiss, 1 ounce||6||2|
** DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents among products within the context of a total daily diet. The DV for vitamin D is currently set at 400 IU for adults and children age 4 and older. Food labels, however, are not required to list vitamin D content unless a food has been fortified with this nutrient. Foods providing 20% or more of the DV are considered to be high sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet.
Personally, I wouldn’t touch the margarine, and am not too keen on the breakfast cereal. Mushrooms didn’t make their list, either, and they can be a good source of vitamin D. I’d prefer whole, raw milk, too. Vitamin D is a FAT SOLUBLE VITAMIN – which means your body can’t use it without fat.
It has been shown that zinc lozenges or syrup taken early in the course of a cold can shorten its duration and severity. WebMD states:
First, zinc interferes with the ability of rhinoviruses, which are responsible for about 80% of all colds, to reproduce. Second, it appears to block their ability to dock on cell membranes and subsequently cause infection.
I generally recommend focusing on nutrient dense foods rather than supplements, but once in a while I make an exception.
If you would like to get your zinc from food sources, the top foods recommended by the National Institute of Health are as follows:
A wide variety of foods contain zinc (Table 2) . Oysters contain more zinc per serving than any other food, but red meat and poultry provide the majority of zinc in the American diet. Other good food sources include beans, nuts, certain types of seafood (such as crab and lobster), whole grains, fortified breakfast cereals, and dairy products [2,11].
Phytates—which are present in whole-grain breads, cereals, legumes, and other foods—bind zinc and inhibit its absorption [2,12,13]. Thus, the bioavailability of zinc from grains and plant foods is lower than that from animal foods, although many grain- and plant-based foods are still good sources of zinc .
|Food||Milligrams (mg) |
|Oysters, 6 medium, breaded and fried||76.7||511|
|Beef shanks, cooked, 3 ounces||8.9||59|
|Crab, Alaska king, cooked, 3 ounces||6.5||43|
|Pork shoulder, cooked, 3 ounces||4.2||28|
|Breakfast cereal fortified with 25% of the DV for zinc, ¾ cup serving||3.8||25|
|Lobster, cooked, 3 ounces||3.4||23|
|Chicken leg, roasted, 1 leg||2.7||18|
|Pork tenderloin, cooked, 3 ounces||2.5||17|
|Baked beans, canned, ½ cup||1.7||11|
|Cashews, dry roasted, 1 ounce||1.6||11|
|Yogurt, fruit, low fat, 1 cup||1.6||11|
|Raisin bran cereal, ¾ cup||1.5–10.8||10–72|
|Chickpeas, ½ cup||1.3||9|
|Cheese, Swiss, 1 ounce||1.2||8|
|Almonds, dry roasted, 1 ounce||1.0||7|
|Milk, whole, 1 cup||1.0||7|
|Chicken breast, roasted, ½ breast with skin removed||0.9||6|
|Cheese, cheddar or mozzarella, 1 ounce||0.9||6|
|Peas, boiled, ½ cup||0.9||6|
|Kidney beans, cooked, ½ cup||0.8||5|
|Oatmeal, instant, 1 packet||0.8||5|
|Flounder or sole, cooked, 3 ounces||0.3||2|
* DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents of products within the context of a total diet. The DV for zinc is 15 mg for adults and children age 4 and older. Food labels, however, are not required to list zinc content unless a food has been fortified with this nutrient. Foods providing 20% or more of the DV are considered to be high sources of a nutrient.
I appreciate that they do mention that phytates can interfere with mineral absorption. As for the boneless, skinless chicken breast, low fat yogurt and instant oatmeal – not for me, thanks.
If you eat a variety of real foods, including plenty of vegetables and fruits, fermented foods, bone broths and organ meats, you’ll be well on your way to getting what you need to help your body stay healthy. In the interest of keeping this post from turning into an e-book, I’m going to stop here with these two vitamins and one mineral, as they have turned up time and again in my research, but you should know that no vitamin or mineral acts independently in your body, and a cross spectrum of nutrition is your best defense.
If you’ve found this post helpful, you may also enjoy the other posts in the series:
and the related post: