Wednesday, October 30, 2013

Vitamin D May Not Help a Cold. Maybe Avoiding Sugar Does.

I just found this from the Vitamin D Council:

Also, readers should be aware (if they are not already) that vitamin D does not prevent all viral respiratory infections. As we noted in correspondence to our first influenza paper, rhinoviruses, the most common cause of the common cold, are not seasonal; that is, they are just as common in the summer as in the winter, and they do not have a lipoprotein coat for antimicrobial peptides to destroy....If you are already taking 5,000 IU a day and you get a cold, chances are that more vitamin D will not help much. No one should take large doses for more than a few days and then only if the infection is severe(1)

However, vitamin D levels are inversely associated with upper respiratory tract infections.(2) If you haven't been taking any vitamin D, a moderate dose might help.

Nevertheless, I have (mostly) gotten over my cold faster than some acquaintances, who came down with colds before I did and are still sick. (One coworker sounded like a one-man sick ward. Same kind of cold as mine, too--lots of mucus and a sore throat.)  Maybe it was the fat fast; maybe it's because I don't knock back any orange juice or lozenges. If you drink three cups of orange juice and take four lozenges, that's 100 grams of sugar. Sugar may suppress your immune system (3) and the vitamin C in the orange juice may or may not help a cold.(4) During an illness, your blood glucose level is already higher than normal; adding another hundred grams of sugar a day could push some people's BG to a toxic level. Going from 100 to 140, for instance, isn't a big leap. In diabetics, infection is more likely to occur with high blood sugar; perhaps that applies to the rest of us, too.

Since people generally don't have an appetite when they have a cold, it's a good time to go on a short fat fast or intermittent fast to reduce inflammation in general, anyway. (My fat fast was a whole lot easier than it was last time. I didn't keep track of calories or fat content, but I didn't eat much, and everything was high in fat. The ketostick today showed light ketones.) I can't say whether the fat fast reduced inflammation or not. But in spite of having a lot of mucus, I wasn't congested after Sunday night, so my nasal passages might not have been very inflamed. (I know the Mucinex helped.)

Anecdotally, low-carbers have few colds and get over them faster than their acquaintances. This may be from taking adequate vitamin D, eating a high-nutrient diet and having normal blood sugar levels.

  1. Newsletter: Even More Vitamin D Questions and Answers by John Cannell, MD. April 1, 2010. 
  2. "Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey."Adit A. Ginde, MD, MPH; Jonathan M. Mansbach, MD; Carlos A. Camargo Jr, MD, DrPH Arch Intern Med. 2009;169(4):384-390. doi:10.1001/archinternmed.2008.560. 
  3. "Dear Mark: Sugar as an Immune Suppressant." by Mark Sisson. Mark's Daily Apple, March 29, 2010. 
  4. "Vitamin C for preventing and treating the common cold" by Harri Hemilä, Elizabeth Chalker and Bob Douglas. The Cochrane Library, July 18, 2007.


Galina L. said...

We have in our family history an account of a person (my mom's uncle) who got a tuberculosis during World War, antibiotics were just discovered not available for a general population then, he sold all valuables he had including his antic furniture,all rugs,only bare walls were left in his dwelling, and he used that money to buy eggs , butter and salted pork fat on a black market. So, he ate high fat high cholesterol foods till he got better, he died from an old age many years later. I suspect during that time of hunger the standard diet was low in sugar anyway.

Lori Miller said...

I'm glad he lived to a ripe old age. In the US, a lot of people used to come to Swedish Hospital here in Denver for treatment of TB; they put the patients in beds out in the sunshine.

Sad to say, though, one of my neighbors in her 60s died of the flu a few years ago. She was on a low-fat diet on doctor's orders.

Lowcarb team member said...

"having normal blood sugar levels." ........
and doing your best to keep them normal I am sure helps everyone to keep as fit and healthy as possible from the common cold to something more serious.

Glad you are feeling better Lori

All the best Jan

Lori Miller said...

Just found this at the diabetes update blog: "Unfortunately, because high blood sugar weakens the immune system, diabetes can create a vicious circle where inflammation raises blood sugar which deactivates the immune system components that should fight the inflammation, allowing the inflammation to increase, and further raising blood sugar."
A bunch of orange juice, toast, crackers, chicken noodle soup and other junk sick people are encouraged to eat may well put non-diabetics at diabetic BG levels.
Slightly raised blood sugar during an illness is probably a good thing--from an evolutionary standpoint, it probably suppressed hunger and allowed people to rest and get well instead of run themselves ragged looking for food.