“Most patients who require vitamin D supplements should take a small daily dose,” Nate Wood, MD, Instructor of General Medicine at Yale Medicine, told Health. “For patients who are severely deficient in vitamin D, a larger weekly dose may be prescribed for the short-term.”
Vitamin D is necessary for our health, especially our bone health and immune system. While it is possible to take enough vitamin D once a week to keep yourself balanced, the best results were found to be a lower dose (1,000-2,000 IUs or 25-50 mcg ) taken daily.
It helps maintain healthy and strong bones and teeth. This is a high dose of vitamin D to be taken once weekly and not meant for daily consumption. It should be taken for a limited period only under a doctor's guidance. It is used for the treatment and prevention of vitamin D deficiency.
Taken in appropriate doses, vitamin D is generally considered safe. However, taking too much vitamin D in the form of supplements can be harmful. Children age 9 years and older, adults, and pregnant and breastfeeding women who take more than 4,000 IU a day of vitamin D might experience: Nausea and vomiting.
If you have severe vitamin D deficiency, your doctor may prescribe a loading dose of up to 300,000IU. This can be taken as: 50,000IU once a week for 6 weeks. 40,000IU once a week for 7 weeks.
The main consequence of vitamin D toxicity is a buildup of calcium in your blood (hypercalcemia), which can cause nausea and vomiting, weakness, and frequent urination. Vitamin D toxicity might progress to bone pain and kidney problems, such as the formation of calcium stones.
Vitamin D can be taken at any time of the day. However, many people prefer to take it in the morning to reduce the potential risk of sleep disturbances.
High doses of vitamin D supplements over time can cause vitamin D toxicity. A condition called hypercalcaemia (where there is too much calcium in your blood) is the most common result of taking too much vitamin D. Signs of this condition include nausea, dehydration and constipation.
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.
In patients with vitamin D levels less than 20 ng/mL, start with 50,000 IUs of vitamin D3 once a week for 6 to 8 weeks. After that, a dose of 800 to 2000 IU per day should be taken to maintain vitamin D levels above 30 ng/mL.
There are quite a few differences between vitamin D and vitamin D3, but the main difference between them is that vitamin D is a fat-soluble vitamin that regulates calcium and phosphorous levels in the body, whereas the vitamin D3 is the natural form of vitamin D produced by the body from sunlight.
Vitamin D is best absorbed when taken after a meal but may be taken with or without food. Alfacalcidol is usually taken with food. Follow all directions on the product package. If you have any questions, ask your doctor or pharmacist.
Therefore, conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn's disease, and cystic fibrosis, can reduce vitamin D absorption.
"Adequate levels of magnesium in the body are essential for the absorption and metabolism not only of vitamin D but of calcium as well," Dean states. "Magnesium converts vitamin D into its active form so that it can help calcium absorption.
Everyone (including children) should consider taking a daily supplement containing 10 micrograms (10µ) of vitamin D (400 IU), particularly during the winter months (October to March). It is specifically recommended that groups at higher risk of vitamin D deficiency take a daily supplement all year round.
Answer: It is not necessary to take vitamin D every day. If you need to take vitamin D because your blood levels are low, you can take it every few days, weekly, or even monthly, because, as you mention, it is fat-soluble and, therefore, stored for future use within the fat in your body.
Unless your doctor recommends it, avoid taking more than 4,000 IU per day, which is considered the safe upper limit.
Vitamin D and sleep: The surprising connection
Early research suggests it is inversely related to melatonin, your sleep hormone. Increasing vitamin D levels may suppress melatonin levels. So, it makes sense that taking it at night could disrupt your sleep.
Growing evidence has demonstrated that vitamin D has a role in sleep regulation [12]. Specifically, vitamin D deficiency (VDD) can increase risk of sleep disorders and is associated with sleep difficulties, shorter sleep duration, and nocturnal awakenings in children and adults [13,14,15].
Can you take vitamin D and magnesium together? Yes. In fact, it's probably best to take both together. Because so many people have low magnesium levels, vitamin D supplements on their own aren't very helpful for a large portion of the population.
If you've been prescribed high-dose vitamin D, work closely with your doctor to monitor your blood levels. It can take three months or more to bring them back up, but once they're good, you can stop the high doses and return to a lower vitamin D supplement for maintenance.
Vitamin D undergoes two hydroxylations in the body for activation. Calcitriol (1,25-dihydroxyvitamin D3), the active form of vitamin D, has a half-life of about 15 h, while calcidiol (25-hydroxyvitamin D3) has a half-life of about 15 days.
Magnesium assists in the activation of vitamin D, which helps regulate calcium and phosphate homeostasis to influence the growth and maintenance of bones. All of the enzymes that metabolize vitamin D seem to require magnesium, which acts as a cofactor in the enzymatic reactions in the liver and kidneys.
Vitamin D deficiency is most commonly caused by a lack of exposure to sunlight. Some disorders can also cause the deficiency. The most common cause is lack of exposure to sunlight, usually when the diet is deficient in vitamin D, but certain disorders can also cause the deficiency.