This is the type of vitamin D that circulates in the blood. Itâs considered a good reflection of how much vitamin D youâve absorbed from sun exposure and taken in from foods. Levels of vitamin D are expressed in nanomoles/liter (nmol/L) or nanograms/milliliter (ng/mL). According to the Office of Dietary Supplements (ODS), the results can indicate the following:
Other Health Conditions. On rare occasions, being tired after a meal or simply sleepy all the time could be a sign of another health problem. Diabetes, anemia, underactive thyroid, celiac disease, food intolerance, and sleep apnea can make post-meal drowsiness worse.
Approximately three hours after eating a complete meal, you should feel hungry. It may occur even sooner if you're eating five to six smaller meals a day. If you don't, it may be for one of the reasons below. 1  Low blood sugar from not eating properly.2  You might feel tired, irritable, lightheaded or jittery, and you don't recognize these feelings as hunger.t may occur even sooner if you're eating five to six smaller meals a day. If you don't, it may be for one of the reasons below. 1  Low blood sugar from not eating properly. 2  You might feel tired, irritable, lightheaded or jittery, and you don't recognize these feelings as hunger.