Is lower heart rate, the lowest was 37bpm during sleep, (recorded on holter monitor), any danger? i am 33 male, 183cm 92kg. have b12 defficiency, d defficiency and chronic sinusitis.

Very complex: It is unusual to have so many uncommon disease conditions. Do you have symptoms of fatigue, shortness of breath, and/or fainting? Have you found out why you are suffering from vit B12 deficiency? Have you been worked up for gluten intolerance? Have you asked your cardiologist re the slow heart rate ? Immune evaluation or CT sinus for the sinus infection? All these need be addressed.

How do you FEEL?: If you're an athlete and not having spells where you pass out, this is fine and you should be proud of it. If you have other evidence of heart pathology, it's your physician's decision whether to have you worked up for some obscure illness. If your B12 and D deficiencies are due to vegetarianism, please begin supplementing; if not, try to find the cause and supplement appropriately.