Last Updated: May 11 2023

Erections occur when the penis fills with blood, making it rigid, longer, and thicker. While erectile dysfunction (ED) has many possible causes, from the neurological to the physical, the ones nutrition can address are vasodilation — the widening of blood vessels to allow greater blood flow — and hormonal imbalances caused by nutritional deficiencies.


The ability to achieve and maintain erections when aroused is a common health issue for many men.[1] While women don’t experience the phenomenon in the same way, inadequate blood flow to female genitalia is also common — and sometimes related to the same phenomena.

Aging is the biggest risk factor for ED, but there are a host of other contributing factors,[2] such as diabetes, vascular disease, low testosterone,[3] and hypothyroidism.[4]

The potential causes of ED generally revolve around vasodilation — the widening of blood vessels — which allows the penis to accommodate more fluid, thus allowing it to become erect. Nitric oxide is a chemical messenger that tells blood vessels to dilate; a breakdown in signaling is a common reason for ED and high blood pressure.

Nitric oxide precursors and substances that lead to greater nitric oxide synthesis are commonly found in drugs and supplements aiming to improve erections. Sex hormones are involved in nitric oxide synthesis, and men with low testosterone are more likely to have ED. Anything that leads to dysfunction in the walls of the blood vessels, such as smoking, inactivity, and excessive body fat, can increase ED risk as well.

Sometimes ED isn’t a breakdown in vasodilation or a hormonal problem but secondary to psychological issues of anxiety and anhedonia — a diminished ability to feel pleasure. In this case, while some libido-enhancing supplements may be useful, the answer may not be found in supplements or dietary modification.

How are erections assessed?

A urologist, who specializes in urinary and sexual issues, is best and can assess ED through a series of medical and sexual history questions. They may also perform a mental health screening and physical exam.

During the exam, your urologist may ask you some of the following questions.

  • How would you rate your confidence that you can get and keep an erection?
  • How often is your penis firm enough for intercourse?
  • How often are you able to maintain an erection during sexual intercourse?
  • Do you have an erection when you wake up in the morning?
  • Do you use illegal drugs, drink alcohol, or smoke?

While it can be uncomfortable, the more accurate your answers, the better medical care your physician can provide.

What affects erections?
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