Normal 24-hour urine calcium concentrations after long-term daily oral intake of vitamin D in doses ranging from 5000 to 50,000 international units in 14 adult hospitalized psychiatric patients.

Many controversies exist regarding vitamin D3 supplementation. These include not only diseases that are responsive to vitamin D supplementation, but also the long-term safety of prolonged daily oral vitamin D3 intake above 4000-10,000 International Units (IU). In particular, supplementation levels that do not result in adverse events, and the upper limits of safe serum 25-hydroxyvitamin D (25OHD) concentrations. Adverse reactions reported to occur with excessive vitamin D intake include hypercalcemia, renal failure, calcium crystal formation, undetectable parathyroid hormone concentrations, and hypercalciuria, all of which are reported to be reversible. To address the long-term safety of vitamin D supplementation, we previously reported data from patients in our hospital who have been voluntarily supplemented with vitamin D3 ranging from 5,000 to 10,000 IU/day since July 2011 as a standard of care for the prevention and treatment of vitamin D deficiency. Historically 90% of patients have agreed to daily supplementation, with most taking 10,000 IU/day. These data indicate no evidence for hypercalcemia, renal failure, calcium crystal formation, nephrolithiasis. or undetectable parathyroid hormone concentrations in patients taking 5000 or 10,000 IU/day for extended periods of time. As another measure for potential vitamin D toxicity, we retrospectively assessed 24-hour urine calcium excretion in 14 individuals on long-term daily oral vitamin D intake ranging from 5000 to 50,000 IU/day to further assess the safety of supplementation using these doses. This included patients taking either 5000 (4), 10,000 (9), or 50,000 (1) IU/day. Time on supplementation ranged from 10 to 102 months. A patient taking 400 IU/day and getting frequent sun exposure was also included. All fifteen 24-hour urine calcium measurements were normal. The current findings complement our experience with over 7000 patients in the past 13 years, indicating that prolonged daily oral intake of vitamin D3 ranging from 5000 to 10,000 IU/day is safe.

Oral and Topical Vitamin D, Sunshine, and UVB Phototherapy Safely Control Psoriasis in Patients with Normal Pretreatment Serum 25-Hydroxyvitamin D Concentrations: A Literature Review and Discussion of Health Implications.

Vitamin D, sunshine and UVB phototherapy were first reported in the early 1900s to control psoriasis, cure rickets and cure tuberculosis (TB). Vitamin D also controlled asthma and rheumatoid arthritis with intakes ranging from 60,000 to 600,000 International Units (IU)/day. In the 1980s, interest in treating psoriasis with vitamin D rekindled. Since 1985 four different oral forms of vitamin D (D2, D3, 1-hydroxyvitaminD3 (1(OH)D3) and 1,25-dihydroxyvitaminD3 (calcitriol)) and several topical formulations have been reported safe and effective treatments for psoriasis-as has UVB phototherapy and sunshine. In this review we show that many pre-treatment serum 25(OH)D concentrations fall within the current range of normal, while many post-treatment concentrations fall outside the upper limit of this normal (100 ng/mL). Yet, psoriasis patients showed significant clinical improvement without complications using these treatments. Current estimates of vitamin D sufficiency appear to underestimate serum 25(OH)D concentrations required for optimal health in psoriasis patients, while concentrations associated with adverse events appear to be much higher than current estimates of safe serum 25(OH)D concentrations. Based on these observations, the therapeutic index for vitamin D needs to be reexamined in the treatment of psoriasis and other diseases strongly linked to vitamin D deficiency, including COVID-19 infections, which may also improve safely with sufficient vitamin D intake or UVB exposure.