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Side Effect: Low Blood Phosphorus (hypophosphatemia)

What is a Low Blood Phosphorus or Hypophosphatemia?

A low blood phosphorus level, also known as hypophosphatemia, is a medical condition where the level of phosphorus in the blood is below the normal range.

What does a Low Blood Phosphorus or Hypophosphatemia look like?

Phosphorus is an essential mineral that plays a critical role in many biological processes, including energy production, bone and teeth formation, and the body’s acid-base balance. If blood phosphorus levels get too low, this can lead to a wide range of symptoms, such as weakness, fatigue, muscle pain, and bone pain. In severe cases, it can even lead to respiratory (lung) and heart failure.

Low Blood Phosphorus (hypophosphatemia)

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Who gets Low Blood Phosphorus (hypophosphatemia)?

Several factors can cause low blood phosphorus levels, including:

Patients with cancer, especially those undergoing chemotherapy, are also at risk of developing low blood phosphorus levels due to the effects of chemotherapy on bone metabolism and renal function.

Additionally,some IV iron formualtions (for example, ferric carboxymaltose, also known as Injectafer®) used to treat iron deficiency anemia may cause a temporay decrease in serum phosphorus, which often resolves within 6 weeks of the last dose.

Tyrosine-kinase inhibitors such as imatinib (Gleevec®), mTOR inhibitors such as temsirolimus (Torisel®), and vascular endothelial growth factor (VEGF) inhibitors such as sorafenib (Nexavar®) can all cause low phosphorous levels.

How do you prevent a Low Blood Phosphorus or Hypophosphatemia?

Preventing low blood phosphorus levels involves maintaining a healthy diet that includes foods rich in phosphorus, such as:

How to treat Low Blood Phosphorus (hypophosphatemia)

Treating low blood phosphorus levels may involve phosphorus supplementation either orally (pill-form) or intravenously (infusions), depending on the severity of the condition. You may also require magnesium or vitamin-d supplements as both of these are needed for your body to absorb phosphate.


1. Adhikari S, Mamlouk O, Rondon-Berrios H, Workeneh BT. Hypophosphatemia in cancer patients. Clin Kidney J. 2021 Apr 15;14(11):2304-2315.

2. Berman E, Nicolaides M, Maki RG, et al. Altered bone and mineral metabolism in patients receiving imatinib mesylate. N Engl J Med. 2006 May 11;354(19):2006-13.

3. Bellini E, Pia A, Brizzi MP, et al. Sorafenib may induce hypophosphatemia through a fibroblast growth factor-23 (FGF23)-independent mechanism. Ann Oncol. 2011 Apr;22(4):988-990.

Created: March 13, 2024 Updated: March 13, 2024