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.
Feeling Tired After a Meal Is Completely Normal. If you feel tired after a meal, thereâs a good chance itâs just your body responding to all of the biochemical changes caused by digestion. In other words, itâs completely normal. However, if the symptom is disruptive and/or changing your lifestyle habits doesnât seem to help, it might not hurt to talk to your doctor.