# About grams, MCG and MG. **URL:** \ **Category:** Factual Questions\ **Created:** [October 1, 2004, 11:07pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117 "2004-10-01T23:07:24Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![ltfire](https://avatars.discourse-cdn.com/v4/letter/l/7ea924/32.png) [@ltfire](https://boards.straightdope.com/u/ltfire)\ **Post date:** [October 1, 2004, 11:07pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/1 "2004-10-01T23:07:24Z")
I take prescription medication for my trigylycerides, and my doctor also recommended that I take Omega 3 fish oil. He said to take 2 to 4 GRAMS per day. The only measurements I can find on the bottle are listed as MG (1000). So, what’s a GRAM, an MG and a MCG, and how do I convert them to the one I want? ---
**Author:** ![bouv](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@bouv](https://boards.straightdope.com/u/bouv)\ **Post date:** [October 1, 2004, 11:10pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/2 "2004-10-01T23:10:23Z")
A milligram is 1/1000 of a gram. So, if one pill (I’m asuming it’s a pill) of fish oil is 1000 mg, then it is one gram. So 2 to 4 of those pills you get you the 2 to 4 grams a day you need. MCG? Never heard of that measurement. What do you have in your medicine cabinet that lists itself in MCG? ---
**Author:** ![\_xiao\_wenti](https://avatars.discourse-cdn.com/v4/letter/_/b782af/32.png) [@\_xiao\_wenti](https://boards.straightdope.com/u/_xiao_wenti)\ **Post date:** [October 1, 2004, 11:27pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/3 "2004-10-01T23:27:12Z")
MCG sounds like it is micrograms. To be written properly it needs a mu (greek letter). Usually the shorthand in ASCII is to write ug as the u looks like a mu without the tail. So 1,000,000 ug (MCG)=1000 mg (MG)=1g (G). In SI, they should also be lowercase, but that’s another story. ---
**Author:** ![Bippy\_the\_Beardless](https://avatars.discourse-cdn.com/v4/letter/b/ac8455/32.png) [@Bippy\_the\_Beardless](https://boards.straightdope.com/u/Bippy_the_Beardless)\ **Post date:** [October 1, 2004, 11:31pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/4 "2004-10-01T23:31:41Z")
And a gram is one thosandth of the weight of one liter of water (though it is not defined in those terms anymore. It is equal to 0.002204622622 lbs according to my calculators convertion function, or 1 lbs is approx 454 grams. ---
**Author:** ![ltfire](https://avatars.discourse-cdn.com/v4/letter/l/7ea924/32.png) [@ltfire](https://boards.straightdope.com/u/ltfire)\ **Post date:** [October 1, 2004, 11:45pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/5 "2004-10-01T23:45:13Z")
> [@bouv](#): > > A milligram is 1/1000 of a gram. So, if one pill (I’m asuming it’s a pill) of fish oil is 1000 mg, then it is one gram. So 2 to 4 of those pills you get you the 2 to 4 grams a day you need. > MCG? Never heard of that measurement. What do you have in your medicine cabinet that lists itself in MCG? It’s a bottle of B-12, and the bottle reads ‘B-12’ 1000 mcg ---
**Author:** ![Bippy\_the\_Beardless](https://avatars.discourse-cdn.com/v4/letter/b/ac8455/32.png) [@Bippy\_the\_Beardless](https://boards.straightdope.com/u/Bippy_the_Beardless)\ **Post date:** [October 2, 2004, 12:10am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/6 "2004-10-02T00:10:22Z")
Are you saying that a Doctor advised you to take 2-4 grams of Vitamin B-12? That sounds a massive dose. as the RDA listed for B-12 is only a few micro grams per day. (From [this](http://www.iom.edu/Object.File/Master/7/296/0.pdf) PDF file) 4 grams of B-12 is over a million times the RDA!!! I susspect the doctor meant take 2-4 grams of fish oil per day. Check back with doctor to be sure. ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [October 2, 2004, 12:35am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/7 "2004-10-02T00:35:34Z")
To get the “mu” character, hold the ALT key and then type 0181 while still holding the ALT key and you get µ Here’s some other special characters: [http://www.1728.com/altchar.htm](http://www.1728.com/altchar.htm) And here’s plenty of converters to use: [http://www.1728.com/indexcon.htm](http://www.1728.com/indexcon.htm) ---
**Author:** ![ltfire](https://avatars.discourse-cdn.com/v4/letter/l/7ea924/32.png) [@ltfire](https://boards.straightdope.com/u/ltfire)\ **Post date:** [October 2, 2004, 12:51am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/8 "2004-10-02T00:51:07Z")
> [@Bippy the Beardless](#): > > Are you saying that a Doctor advised you to take 2-4 grams of Vitamin B-12? > > That sounds a massive dose. as the RDA listed for B-12 is only a few micro grams per day. (From [this](http://www.iom.edu/Object.File/Master/7/296/0.pdf) PDF file) 4 grams of B-12 is over a million times the RDA!!! I susspect the doctor meant take 2-4 grams of fish oil per day. Check back with doctor to be sure. No, you mis-read. bouv asked me where I got the mcg from and I said it was on a bottle of B-12. My original question was for fish oil. I needed the definition of gram, mg and mcg. ---
**Author:** ![Epimetheus](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@Epimetheus](https://boards.straightdope.com/u/Epimetheus)\ **Post date:** [October 2, 2004, 1:09am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/9 "2004-10-02T01:09:17Z")
Well, mcg is often used in Prescription drugs as well as vitamins and such. Very rarely is a Mu symbol used. (regarding the mcg being a poor way to write it) ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [October 2, 2004, 1:41am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/10 "2004-10-02T01:41:09Z")
In case it isn’t clear yet, a mcg is 1/1000 of a mg. A mg is 1/1000 of a gram. ---
**Author:** ![Laughing\_Lagomorph](https://avatars.discourse-cdn.com/v4/letter/l/6bbea6/32.png) [@Laughing\_Lagomorph](https://boards.straightdope.com/u/Laughing_Lagomorph)\ **Post date:** [October 2, 2004, 1:48am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/11 "2004-10-02T01:48:33Z")
As a molecular biologist I deal in micrograms daily. We usually write it ug or with the mu symbol (the control-alt trick isn’t working for me). We never use mcg but I recognized what it was. ---
**Author:** ![chaoticbear](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@chaoticbear](https://boards.straightdope.com/u/chaoticbear)\ **Post date:** [October 2, 2004, 3:02am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/12 "2004-10-02T03:02:32Z")
so re: the pill that is 1000 mcg, it works out to 1 mg. ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [October 2, 2004, 3:11am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/13 "2004-10-02T03:11:29Z")
**Lagomorph** No it’s just the ALT key (not CTL and ALT) Give it another try and your molecular biologist co-workers will be impressed. Why type mcg when you can type µg ? (I have heard on the SDMB that the ALT key characters work for some folks and not for others). ---
**Author:** ![asterion](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@asterion](https://boards.straightdope.com/u/asterion)\ **Post date:** [October 2, 2004, 3:35am UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/14 "2004-10-02T03:35:12Z")
You have to use the number pad to get it to work, though. ---
**Author:** ![Laughing\_Lagomorph](https://avatars.discourse-cdn.com/v4/letter/l/6bbea6/32.png) [@Laughing\_Lagomorph](https://boards.straightdope.com/u/Laughing_Lagomorph)\ **Post date:** [October 2, 2004, 7:12pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/15 "2004-10-02T19:12:16Z")
> [@wolf\_meister](#): > > **Lagomorph** > No it’s just the ALT key (not CTL and ALT) > Give it another try and your molecular biologist co-workers will be impressed. > > Why type mcg when you can type µg ? > > (I have heard on the SDMB that the ALT key characters work for some folks and not for others). I mistyped before, I wasn’t using the CTL key, just the ALT. But I was also not using the number keypad: µ _voila_ ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [October 2, 2004, 7:44pm UTC](https://boards.straightdope.com/t/about-grams-mcg-and-mg/267117/16 "2004-10-02T19:44:40Z")
This also works for many people: [symbol]m[/symbol] results in [symbol]m[/symbol]