Depletions

Taking phenytoin may deplete calcium, phosphate, vitamin B9, vitamin D, and vitamin K.

Calcium

Calcium, along with vitamin D, keeps your bones strong and healthy.

Low levels of calcium may cause:

• Muscle cramps
• Numbness or tingling in toes and feet
• Irregular heartbeat
• Depression
• Bone pain
• Spinal problems
• Seizures

Vitamin B9 (Folic Acid)

Low levels of folic acid in the body may be linked to:

• Anemia
• Heart disease
• Birth defects

Symptoms may include:

• Weakness
• Mouth sores
• Swollen tongue
• Depression
• Poor growth

Vitamin D

Vitamin D, along with calcium, keeps your bones strong and healthy.

Low levels of vitamin D may cause:

• Increased risk of osteoporosis
• Softening of the bones, called rickets in children and osteomalacia in adults
• Fractures even on minor injury
• Muscle cramps
• Seizures
• Numbness or tingling in toes and feet

Vitamin K

The major symptom of vitamin K deficiency is that your blood does not clot as it should. Low levels of vitamin K may cause:

• Easy bruising
• Bleeding even on minor injury
• Bleeding gums
• Nosebleeds
• Women may have heavy periods

Lack of vitamin K may also cause internal bleeding. This can be life threatening.

Potassium

Taking phenytoin may deplete potassium.

Symptoms of potassium deficiency include:

• Nausea and vomiting
• Tiredness
• Drowsiness
• Feeling of apprehension
• Weakness
• Muscle pain and weakness (mostly in the legs)
• Muscle cramps
• Strong, rapid or irregular heartbeat

Phosphorous

Phosphorus deficiency is rare, but low levels can cause:

• Muscle pain and weakness
• Bone pain
• Confusion
• Numbness and tingling in feet and toes
• Loss of appetite
• Increased risk of infections
• Trouble breathing
• Seizures
• Irregular heartbeat

Editorial Note

The information presented here covers some of the nutrients that may be affected when you take certain medicines. If you have any of these signs and symptoms, it does not always mean you have low levels of these nutrients.

Factors that affect the level of nutrients are:

• Your medical history
• Diet
• Lifestyle
• How long you have been taking the medicine

Please talk to your health care provider. They can best address your health care needs and see if you are at risk for low levels of any nutrients.

Supporting Research

Asiedu DK. Vitamin D deficiency. In: Ferri FF, ed. Ferri's Clinical Advisor 2017 . Philadelphia, PA: Elsevier; 2017:1357-1358.

Asiedu DK. Vitamin deficiency (Hypovitaminosis). In: Ferri FF, ed. Ferri's Clinical Advisor 2017 . Philadelphia, PA: Elsevier; 2017:1359-1360.

Dominiczak MH, Broom JI. Vitamins and minerals. In: Baynes JW, Dominiczak MH, eds. Medical Biochemistry . 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 11.

Greenbaum LA. Vitamin K deficiency. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 53.

Gold Standard Drug Database. Drug Monograph: Ethotoin 2016. www.clinicalkey.com/#!/content/drug_monograph/6-s2.0-1332 . Accessed July 14, 2016.

Gold Standard Drug Database. Drug Monograph: Fosphenytoin 2016. www.clinicalkey.com/#!/content/drug_monograph/6-s2.0-269 . Accessed July 14, 2016.

Gold Standard Drug Database. Drug Monograph: Phenytoin 2016. www.clinicalkey.com/#!/content/drug_monograph/6-s2.0-232 . Accessed July 7, 2016.

James WD, Berger TG, Elston DM. Nutritional diseases. In: James WD, Berger TG, Elston DM, eds. Andrews' Diseases of the Skin . 12th ed. Philadelphia, PA: Elsevier; 2016:chap 22.

Leone KA. Calcium, magnesium, and phosphorus. In: Adams JG, ed. Emergency Medicine . 2nd ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 166.

Osborn MB. Potassium. In: Adams JG, ed. Emergency Medicine . 2nd ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 165.

Sachdev HPS, Shah D. Vitamin B complex deficiencies and excess. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 49.

Smogorzewski MJ, Stubbs JR, Yu ASL. Disorders of calcium, magnesium, and phosphate balance. In: Skorecki K, Chertow GM, Marsden PA, Yu ASL, Taal MW, eds. Brenner and Rector's The Kidney . 10th ed. Philadelphia, PA: Elsevier; 2016:chap 19.

Yu ASL. Disorders of magnesium and phosphorus. In: Lee G, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier; 2016:chap 119.