Can taking vitamins cause increased urination (polyuria)?

From the Guidelines

Taking high-dose vitamin C supplements, typically over 1,000 mg daily, can cause increased urination due to the excess being filtered by the kidneys and excreted in urine. This is because vitamin C can be metabolized to oxalate, and high intake may increase urinary oxalate excretion, as demonstrated by a metabolic trial that showed a 22% increase in urinary oxalate excretion with 1000 mg of supplemental vitamin C consumed twice daily 1. When considering the impact of vitamins on urination frequency, it's essential to focus on water-soluble vitamins like vitamin C, as they are more likely to be excreted in urine when taken in excess.

Some key points to consider:

• High-dose vitamin C supplements can increase the risk of calcium oxalate stone formation, particularly in individuals with hyperoxaluria 1.
• The relation between vitamin C intake and stone formation risk is observed after adjusting for dietary potassium intake, suggesting that dietary sources of vitamin C, which are often high in potassium, may not need to be restricted 1.
• If you're taking multivitamins or individual supplements and notice increased urination, this is generally normal and not cause for concern unless accompanied by other symptoms like pain or unusual thirst.
• It's crucial to be aware of the potential effects of high-dose vitamin supplements on urination frequency and overall health, especially for individuals with pre-existing kidney stone issues or other kidney problems.

From the Research

Vitamin Intake and Urination Frequency

• The relationship between vitamin intake and urination frequency is complex and depends on various factors, including the type of vitamin, dosage, and individual characteristics 2, 3, 4.
• Some studies suggest that high-dose vitamin C intake may increase the risk of urinary storage symptoms, such as frequency and urgency, in women 3, 4.
• In contrast, dietary vitamin C intake has been associated with lower odds of progression of daytime storage symptoms in men and urgency symptoms in women 3.
• Vitamin D deficiency has been linked to an increased risk of overactive bladder and urinary incontinence, while vitamin D supplementation may reduce the risk of urinary incontinence 2.

Specific Vitamins and Urination Frequency

• Vitamin C: high-dose intake may increase urinary storage symptoms in women, while dietary intake may have a protective effect in men and women 3, 4.
• Vitamin D: deficiency may increase the risk of overactive bladder and urinary incontinence, while supplementation may reduce the risk of urinary incontinence 2.
• Other vitamins: the evidence is limited, but some studies suggest that high-dose intake of fat-soluble vitamins (A, E, D) and folic acid may cause adverse events, including increased urination frequency 5.

Food and Drinks Impact on Urine Production

• Certain foods and drinks, such as those high in sodium, caffeine, and alcohol, may increase urine production, while others, such as milk and orange juice, may decrease it 6.
• The impact of food and drinks on urine production is influenced by multiple factors, including composition, metabolite load, and the presence of specific diuresis-promoting substances 6.