Over 18% of the population exceeds the NIH daily recommended allowance ( RDA) of 600–800 IU, [2] by taking over 1000 IU, which suggests intentional supplement intake. [165] There is also a type of vitamin D called calcipotriol, which sounds similar to colecalciferol. Calcipotriol is used to treat the skin condition caused by plaque psoriasis. Key facts If your doctor has prescribed this medication, take as directed by your doctor. Your dosage is based on your medical condition, amount of sun exposure, diet, age, and response to treatment. VDR activation in the intestine, bone, kidney, and parathyroid gland cells leads to the maintenance of calcium and phosphorus levels in the blood (with the assistance of parathyroid hormone and calcitonin) and to the maintenance of bone content. [1] [19] Taking too much colecalciferol can cause calcium and phosphate to build up in your body (hypercalcaemia).

Manufactured foods fortified with vitamin D include some fruit juices and fruit juice drinks, meal replacement energy bars, soy protein-based beverages, certain cheese and cheese products, flour products, infant formulas, many breakfast cereals, and milk. [136] [137]Recommendations on recommended 25(OH)D serum levels vary across authorities, and vary based on factors like age. [2] US labs generally report 25(OH)D levels in ng/mL. [150] Other countries often use nmol/L. [150] One ng/mL is approximately equal to 2.5 nmol/L. [151] Colecalciferol comes as chewable, dissolvable (soluble) and melt-in-the-mouth (orodispersible) tablets, capsules, a syrup, and oral drops. For all forms of vitamin D (sunlight, food, and supplements), the recommended dosage is 4,000 IUs for people nine years of age or older. Without a blood test I would not recommend going higher than that. Side Effects of D3 In general, no good evidence supports the commonly held belief that vitamin D supplements can help prevent osteoporosis. [13] Its general use for prevention of this disease in those without vitamin D deficiency is thus likely not needed. [12] For older people with osteoporosis, taking vitamin D with calcium may help prevent hip fractures, but it also slightly increases the risk of stomach and kidney problems. [64] A study found that supplementation with 800IU or more daily, in those older than 65 years was "somewhat favorable in the prevention of hip fracture and non-vertebral fracture". [65] The effect is small or none for people living independently. [66] [67] Low serum vitamin D levels have been associated with falls, and low bone mineral density. [68] Taking extra vitamin D, however, does not appear to change the risk. [69]

Vitamin D is one of the body’s most important vitamins, helping it with a variety of tasks: Vitamin D contributes to the normal function of the immune system and is very important for the body’s structural system, maintaining normal bone and muscle function. Vitamin D3 also contributes to the normal absorption and utilisation of calcium and phosphorus. Because Vitamin D and calcium are related too much Vitamin D can lead to Calcium issues. These issues include, Hypercalcemia, Kidney Stones and Kidney damage.

The European Food Safety Authority (EFSA) in 2016 [117] reviewed the current evidence, finding the relationship between serum 25(OH)D concentration and musculoskeletal health outcomes is widely variable. They considered that average requirements and population reference intakes values for vitamin D cannot be derived, and that a serum 25(OH)D concentration of 50 nmol/L was a suitable target value. For all people over the age of 1, including women who are pregnant or lactating, they set an adequate intake of 15 μg/day (600 IU). [117] Speaking with your doctor can help determine the right amount of vitamin D for you. Blood samples are needed to run a 25-hydroxy (or 25-OH) vitamin D test. This blood test is best way to determine how much Vitamin D is in your body. Sintzel MB, et al. Vitamin D and Multiple Sclerosis: A Comprehensive Review. Neurol Ther. 2018;7(1):59-85. Vitamin D3, also known by its other alias cholecalciferol, is vitamin D in its natural form–the kind produced in your body as it absorbs sunlight. However, recent studies are beginning to find that vitamin D2 may be as effective as vitamin D3.