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 sleepy after meals is a common symptom of insulin resistance, a risk factor for diabetes. Insulin resistance is common today and is a stepping-stone to diabetes. Overeating and eating a diet high in sugar and starchy foods causes insulin resistance. These foods include breads, rice, pasta, pastries, chips, potatoes, soda, sweet coffee drinks, and more.