In summary, long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe.
In addition, taking a supplement that contains too much vitamin D can be toxic in rare cases. It can lead to hypercalcemia, a condition in which too much calcium builds up in the blood, potentially forming deposits in the arteries or soft tissues. It may also predispose people to painful kidney stones.
Taking more than 4,000 IU a day of vitamin D might cause: Upset stomach and vomiting. Weight loss and not wanting to eat. Muscle weakness.
Taking 5000 IU of vitamin D3 daily is generally considered safe for most people, especially those with low blood levels of vitamin D. The upper limit for adults is typically around 4000 IU per day, but higher doses may be prescribed for specific deficiencies under medical supervision.
Key takeaways. It can take four weeks to four months of daily vitamin D supplementation to notice health improvements. The timeline is affected by factors like supplement type and individual health conditions.
Optimum intake
There is some uncertainty about the amounts of vitamin D a person should consume. The National Academy of Medicine recommend a daily intake of 600 international units (IU) for adults aged 19–70 years and 800 IU per day for individuals aged 70+ years.
Vitamin D3 is removed slowly from the body because it can go into fat tissue. It takes about two months for half the excess to be removed from the body, but because the active forms are removed more quickly, toxicity from excess vitamin D3 usually only lasts for weeks, not months.
Vitamin D 5000 IU is a high-dose supplement that can help treat vitamin D deficiency, which occurs when people don't get enough vitamin D through the sun or their diet.
The effect of equivalent oral doses of vitamin D3 600 IU/day, 4200 IU/week and 18,000 IU/month on vitamin D status was compared in a randomized clinical trial in nursing home residents. A daily dose was more effective than a weekly dose, and a monthly dose was the least effective.
Daily supplementation with 5000 IU vitamin D3 reduces influenza-like illness in healthcare workers.
In our most recent study of 146 vitamin D-deficient, statin-intolerant patients,[48] the amount of vitamin D3 supplementation used was 50,000-100,000 units/week, and there was no adverse effect at this level of supplementation.
Too much vitamin D can be toxic. The recommended maximum intake is 25 mcg (1,000 IU) for infants and 50 mcg (2,000 IU) for children and adults with normal kidney function.
You can become deficient in vitamin D for different reasons: You don't get enough vitamin D in your diet. You don't absorb enough vitamin D from food (a malabsorption problem) You don't get enough exposure to sunlight.
So, when it comes to vitamin d deficiency treatments, how long till you start to feel better? Those with the lowest levels should feel an improvement after just a few days, while those who only need to top up their levels may have to wait a week or two before they begin to feel healthier and more energised.
Because vitamin D is fat soluble, its absorption depends on the gut's ability to absorb dietary fat [4]. Fat malabsorption is associated with medical conditions that include some forms of liver disease, cystic fibrosis, celiac disease, Crohn's disease, and ulcerative colitis [1,63].
It is not safe to take 5000 IU of vitamin D3 every day. High doses such as 5,000 IU can lead to vitamin D toxicity. The upper safety limit for daily intake is 4,000 IU of vitamin D for adults and children above 12 years of age.
This study demonstrates that the administration of oral cholecalciferol 5,000 IU daily is superior to 2,000 IU daily for 3 months to treat mild to moderate vitamin D deficiency. These dosages are safe and effective and results in improvements in parathyroid hormone activity and muscle strength.
Adults aged up to 70 years old should be getting at least 600 IU. Adults older than 70 should be getting at least 800 IU of vitamin D. However, some sources say you should consume up to 1000 IU of vitamin D past the age of 70.
As described previously, the products of vitamin D metabolism are excreted through the bile into the feces, and very little is eliminated through the urine. This is in part due to renal reuptake of vitamin D metabolites bound to DBP, as mediated by the cubilin–megalin receptor system (Willnow and Nykjaer, 2005).
Ideally it's best to quit gradually in order to give your body a chance to adjust. You're least likely to struggle through the withdrawal process if you take several weeks to decrease how much you take.
If you choose to take vitamin D supplements, 10 micrograms a day will be enough for most people. Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful. This applies to adults, including pregnant and breastfeeding women and the elderly, and children aged 11 to 17 years.