The importance of vitamin D for optimal wellness has long been known in holistic medical literature. Vitamin D helps calcium to be absorbed from the digestive system into blood, ensuring a healthy bone metabolism and preventing osteoporosis. By way of optimizing the levels of calcium in the blood, vitamin D doses also help prevent muscular spasms, cramps, and pains.
In recent years, vitamin D has received more positive press than ever before. This is because of vitamin D’s unique and potent anti-microbial and anti-inflammatory properties, as well as its ability to improve cellular immunity; people with lower-than-normal levels of vitamin D may get sick more easily than those who with higher levels.
Recommended Daily Allowance vs. Overuse
While the Recommended Daily Allowance (RDA), issued by the National Institute of Health (NIH) is 600 IU/day for adults, physicians often note that many patients take unjustifiably high doses of vitamin D. The downside of treating a steroid molecule like vitamin D as a harmless candy is that it is fat-soluble, and accumulates in the tissues, with a potential for toxicity. In fact, NIH points out that people with laboratory levels of vitamin D over 100 are likely to have toxic side effects such as headache, dizziness, and lethargy due to overly high levels of calcium in the blood.
One Canadian study focused on the effect of different doses of vitamin D on the rate of bone loss. A total calcium intake of 1,200mg/day was used as a reference point as it is a standard of care in most countries. The study found that, the higher the doses of vitamin D supplementation used, the higher was the incidence of side effects, including very high levels of calcium in the urine, promoting kidney stones.
The incidence of side effects was only 3% in people who took up to 4,000 IU of vitamin D daily, but the whopping 10% of people who took 10,000 IU daily had developed toxicity. It was postulated that high-dose vitamin D creates a certain biochemical stress on the body, whereby the body’s natural mechanisms regulating calcium metabolism get overwhelmed.
My advice is that over-the-counter vitamin D should NOT be used indiscriminately. It would be prudent to speak to your doctor about getting your levels checked and get supplementation recommendations based on your unique needs.
