How Long Should You Wait To Retest Your Vitamin D Levels After Starting A Supplement?

Vitamin D is essential for our health but almost half of Americans don't get enough of this vitamin in their diets (via Healthline). Vitamin D is responsible for various functions, including immune system health and keeping bones and muscles strong (via National Institutes of Health). It is difficult to get enough of this vitamin through food and sunshine alone, so many people choose to take a supplement.

If you have recently started taking a vitamin D supplement, you probably want to know if it's actually working. According to Mindbodygreen, you'll need to be patient when taking a supplement. It takes a while for your overall vitamin D levels to increase even when taking a vitamin consistently. You should wait about three months before having your vitamin D levels checked by a healthcare practitioner. This will ensure that your vitamin D levels are consistent and will help your doctor know whether you need to increase your dose or not.

Should you take a vitamin D supplement?

According to Mindbodygreen, many people could benefit from taking a vitamin D supplement. About 41% of Americans don't get enough of this vitamin, partly because it is so difficult to get it through food. Over 90% of Americans don't get enough vitamin D through food. You can also get vitamin D through sunshine. When ultraviolet B (UVB) rays from sunlight hit our skin, our bodies produce this vitamin naturally (via Harvard Health Publishing). However, getting plenty of sunshine isn't always possible, especially in the winter.

The further you live away from the Equator, the less likely you will be to access UVB sunlight during the winter months. People who live in the northern U.S. states, for example, will be able to produce very little vitamin D from sunlight between November and February (via Oregon State University). Wearing sunscreen also blocks UV rays and reduces the amount of vitamin D your body can produce from the sun. With these factors taken into consideration, taking a vitamin D supplement can be beneficial for most people.