What may lead to hemoglobin levels in the blood dipping below normal?

A diet lacking in iron can significantly affect hemoglobin levels in the blood. Hemoglobin is a crucial protein in red blood cells responsible for transporting oxygen throughout the body. Iron is an essential component of hemoglobin, and without sufficient iron intake, the body cannot produce enough healthy hemoglobin. This can lead to conditions such as iron-deficiency anemia, where the blood's hemoglobin levels dip below the normal range, resulting in fatigue, weakness, and other health issues.

In contrast, while excessive exercise and dehydration might influence blood parameters, they typically do not directly result in low hemoglobin levels like an iron-deficient diet does. High calorie intake does not correlate with lowering hemoglobin; instead, it might contribute to overall energy levels if the calories consumed are from balanced sources. Hence, an iron-deficient diet is a clear and direct cause of suboptimal hemoglobin levels.