Okay.
 

First, yes, you are basically B12 deficient. No one should accept B12 levels in the low 300's as normal. Too many doctors are still way behind in looking at the lab ranges without question, despite guidelines from the Family Practice Notebook to numerous medical texts saying that the ranges are outdated. (In Japan, the bottom of the range, depending on lab, starts at 500 or even 550.)

It's certainly possible that B12 deficiency is causing many or most of your symptoms, but so can celiac/gluten sensitivity. Your reports of symptomatic easing after stopping gluten ingestion strongly hints that you need to get a celiac panel done at the very least--B12 deficiency can certainly be secondary to malabsorption caused by celiac (although there are numerous other causes). Other nutrients can be malabsorbed as well, so a good idea would be to get a celiac panel testing transglutaminase IgA and IgG, anti-gliadin IgA and IgG, and total IgA (people who naturally produce low immunoglobulin A levels can have false negative results on the other IgA tests, so measuring that is prudent).

Meantime, continue supplementing with B12--though you're likely to get better absorption with lozenges rather than the spray. The tablets come in 1000mcg to 5000mcg sizes and are quite inexpensive, and are designed to megadose so even if you do have gastrointestinal malabsorption, you will passively absorb 1-2% of the dose and rebuild stores. B12 has no known toxicity level, so you can do 5000mcg/day if you want--some report feeling revved up and energized at those levels, so monitor that.

And, if possible, it's a good idea to get an activated form of B12--methylcobalamin--rather than the cyanocobalamin, so that there are fewer metabolic hoops to jump through in absorbing the cobalamin (which is particularly important if you are one of the minority of people who due to genetic chemistry has trouble methylating organic molecules).

I feel as though I need a shot a day!

I had my first b12 shot 3.5 weeks ago on a friday and I've had one each friday since. So 4 in total now. I feel better on saturday and sunday. partly because I'm taking it easy, but also because of the shots I think. But then on Monday it all goes downhill. its a tough day for me anyways since I need to be at work by 6:30am and I dont usually leave until after 6. But by the end of the day I feel as though all the progress I made over the weekend disappears and then I end up feeling worse.

When I first started taking the injections, I had been getting lightheaded and mentally unfocused throughout the day. thankfully that seems to be getting better as the weeks have gone by. but the random muscle twitching and pins and needles seems to be getting worse with each week. And today was the first day where I was getting tremors in my hands when holding things or working on my computer. My muscles just feel weak. Its only the couple days after the shot do I feel as though I get better. Then I start work and it all gets worse... almost as if I'm allergic to my job haha.

Supposed to see doc early next week as my weekly shots are over. She wanted to do one a week for the first month. And then go to monthly. But I think I need to go back to weekly shots if not more regularly. That or I just need to quit work.

I'm sorry to ask such a silly question, but I'm trying to research about ways to regulate my metabolism and I'm wondering if B-12 is something that does that?

I am taking 1000mcg of methyl b12 and methyl 800mcg and both brands are jarrow. I have been taking them for 3 days and yet to feel any difference. Is their something wrong?

3 days is a very short time to fix anything.
These nutrients are not drugs. It takes quite a while
(At least a month and ideally 3 months )
To notice improvements.

Don't forget to take the B12 on an empty
Stomach. ;)

Thanks. Also how long should i stop taking b12 before a blood testing?

About a week. B12 can exit the blood serum
In Bput 72 hrs but a week would be better
If you can do it.

Oh really? I didnt know that. I had a blood test and my b12 was low 300s. Started taking pills for a couple weeks. Had recently moved and wanted another opinion since first doc just told my odd muscle twitching and mental fatigue was nothing to worry about. So I saw a new doc who did seem alarmed by my low b12. but she wanted to do another blood test. fast forward a month which was yesterday and found out the new b12 reading was in 500s. but I had been taking b12 every day including the morning of the 2nd blood test. I asked if that would affect my reading but she never really answered.

When i used to work in a clinic setting they had a huge reference
On drug pharmacology for hospital use . When this book was replaced some of us got to have the older version to take
Home. It 's exact title escapes me here on vacation -- something
Like JHCP or something like that-- the B 12 excretion data
Was for the injections only and mentioned the 72 hrs.
This is probably why people who come here getting shots
Once a month complain of significant let downs days after
The monthly dose.

The effects of oral would be smaller but still will show in
The serum as artificial elevations to some extent.

Doctors know very little pharmacology about the drugs
They prescribe... And little to nothing about vitamins as
A rule. A good test is to ask what B2 is. You will get
The same blank look most Likely.(it is riboflavin).

500 is not a good result. Most of us here want 1000 pg/ml.

This is frustrating. I've been taking b12 vitamins for 7 weeks now. But only 4 weeks at 5000. And I've had four b12 injections but havent had one in 2.5 weeks now. Doc wanted to do weekly and then turn them into monthly so next injection is next week.

I keep reading how it takes months and maybe years to get better. But I had only really noticed the symptoms about 3 months before I was told about the b12 and took my first pill. So I was hoping my recovery would be a little quicker since the damage is hopefully not as severe. But instead of getting better I feel like I'm getting worse. Today was the worst day yet. Tingling in legs. lightheaded. really tired. muscles sore. hands shaky. Didnt sleep well. And some of these symptoms I didnt really notice until after I started taking the pills.

I've also read that when you start taking these vitamins that you may feel good initially(a honeymoon period) only to potentially feel much worse for awhile but you finally start to recover. But its just hard to stay positive. I guess I just wish I knew B12 was the problem. And then I wouldnt have these lingering doubts in my mind that it could be something else when I feel worse. And my Doc's keep telling me I'm just stressed and it's nothing. But it's not nothing. I know I feel off. And I'm still just not getting better.

But I'm trying real hard to stay positive. And I really havent been taking these pills all that long. I just wish there was improvement. Something to hang my hat on.