Which nutrient levels can be negatively affected by alcohol abuse?

The correct choice highlights the specific nutrients that can be adversely impacted by excessive alcohol consumption. Alcohol abuse has a particularly detrimental effect on vitamin levels due to its interference with absorption, utilization, and metabolism.

Vitamin A is affected because alcohol can impair the liver's ability to convert beta-carotene to vitamin A, leading to deficiencies. Folate is critical for DNA synthesis and repair, and alcohol can disrupt its absorption in the intestines, further leading to deficiencies that may have severe health implications, such as anemia and increased homocysteine levels. Thiamine (vitamin B1) is especially crucial as it plays a role in energy metabolism and nerve function; alcohol impairs its absorption and can lead to Wernicke-Korsakoff syndrome, a serious neurological disorder.

Each of these nutrients is essential for overall health, and their deficiencies due to alcohol abuse can lead to various health complications. This choice correctly captures the direct impacts of alcohol on nutrient levels that are vital to maintaining health and well-being.