Welcome @Mary Em, Vitamin D plays an essential role in producing serotonin and minimizing oxidative stress, both of which can affect the migraine brain. Low vitamin D levels may contribute to migraine.  42% of Americans are deficient in vitamin D, 60% of UK adults and up to 75% northern Canadians are deficient in vitamin D.  Virtually all Celiac Disease sufferers are vitamin D deficient. I have been taking 10,000 IU of vitamin D daily since 2015.  In 2019 my 25(OH)D blood test was 47 ng/ml.  Another two years to get up to 80 ng/ml (equal to 200 nmol/L) the normal homeostasis level, where is stays as long as I continue taking oral vitamin D.   Thiamine (vitamin B1) has been associated with a lower risk of migraine. You might start by taking significant amounts of vitamin D and Thiamin supplemental to increase your levels.  If available to you there are blood tests that will give you a baseline.  Worth checking out. Just eating a gluten free diet does stop the ongoing damage that gluten causes, but it does not replenish the vitamin and mineral malnutrition caused by years of undiagnosed Celiac Disease. I also take: Morning 6am or waking. Clonidine 0.1 mg (Blood pressure) Vitamin D 10,000 IU (250 mcg) DHEA 100 mg   Midmorning 500 mcg Iodine 10 drops of Liquid Iodine   Once a day, midafternoon B1 Thiamin 250 mg B2 Riboflavin 100 mg B3 Nicotinic Acid 500 mg B5 Pantothenice Acid 500 mg Vitamin C 500 mg Selenium twice a week 200 mcg  

I have a few times but I have other health problems made worse by the reaction. The main one being a migraine disorder, so really it was the migraine that knocked me out not the gluten. The gluten just set off everything.

I’m have a vitamin D deficiency. I’m still waiting on a qualitative fat test to see if I have malabsorption. 

@jmiller93, Some of us are seronegative and don't test positive on tTg IgA tests.  Anemia, diabetes, and Thiamine deficiency can cause false negatives on Celiac panels.  Have you been checked for nutritional deficiencies?  Iron? Thiamine?  Vitamin B12?  Vitamin D?  Only one Celiac markers is needed to develop the active disease.   I agree a gluten free diet trial is worth a try.

@HWB, Have you been checked for SIBO?  Small Intestinal Bacterial Overgrowth will cause constipation and chemically breath.   The best way to get rid of SIBO is to go on a ketogenic/Paleo diet, like the Autoimmune Protocol Diet.  It starves out the carbohydrate loving bacteria and allows good bacteria to repopulate the small intestine.   The SIBO bacteria can communicate with the brain along the gut-brain axis, making you crave carbs, and in return, the SIBO bacteria can mess with your immune system by lowering inflammation and producing endorphins.  So, it's no wonder you feel better eating sugar.   I took high dose (500-1000 mg/day) Benfotiamine (Thiamine) which promotes intestinal healing and helps keep bacterial in check.  Thiamine and Benfotiamine are safe and nontoxic even in high doses.  High doses (500-1000 mg) every day are required to get results.  The body responds differently to high doses.  Got rid of my SIBO like this.  It was tough, but Celiac makes you stronger.