Updated: Jul 9
Vitamin D is an essential nutrient that your body needs an adequate supply of in order to function properly. Primarily, your body uses vitamin D to absorb calcium and promote strong bone growth and development. More likely than not your parents told you to drink milk growing up because it would help you grow “strong and tall,” which is true to some extent (genetics play the primary role but getting your recommended vitamin D definitely helps). Though milk is a good source of vitamin D, you can also get it through sunlight, a well-balanced diet, and even a UV lamp if you need.
Vitamin D is good for much more than just healthy bones, it can help prevent heart disease, boost weight loss, and much more. It is a very versatile nutrient which is why you can find it in almost every multivitamin and health supplement, but why is it included in hair loss supplements? Is there a connection between vitamin D and hair loss?
This article is going to take a closer look at the relationship between vitamin D and hair loss to help you better understand the connection and decide if it is something you want in your hair loss supplement.
Vitamin D deficiency and hair loss
Vitamin D deficiency is very common, so common in fact that it is estimated that nearly 42% of Americans and over 1 billion people worldwide are vitamin D deficient, that’s nearly 1 in 8 people.
People become vitamin D deficient for many reasons including not enough sunlight exposure and poor diet (it is more common in vegans because vitamin D occurs naturally in meat). It can also be the result of conditions like Crohn’s disease, cycstic fibrosis, and several other conditions that do not allow your body to properly absorb vitamin D. It is always best to talk to your doctor to determine the underlying cause of your deficiency. But how is it linked to hair loss?
Scientists aren’t entirely sure. Several studies (1,2) found that vitamin D receptors in the body play an important role in the initiation of the anagen (growth) stage of the hair cycle. This may have implications for people with androgenic alopecia (pattern hair loss) relating to the process of miniaturization. During miniaturization, the growth phase of hair follicles is shortened, meaning they slowly grow shorter and shorter during each cycle until they eventually don’t grow at all. If there is a connection between ineffective vitamin D receptors and the miniaturization process then the implications for vitamin D and pattern hair loss would be much stronger, but more research is needed to explore that connection.
The fact that vitamin D receptors are inherently connected to the hairs growth cycle may provide some explanation to the link between low vitamin D levels and hair loss. If the growth phase is not activated, or activated later than it should be, the hair will not grow as long as the previous cycle. Though the connection between androgenic alopecia and vitamin D is purely speculative at this point, there is an established link between low vitamin D and alopecia areata (patchy hair loss). Although alopecia areata is much less common than pattern hair loss, there is some crossover between the mechanisms involved in each of them, which should bring more attention to scientists for the exploration of vitamin D and hair loss more in depth.
Summary of what we know vs. what we don’t
We know that there is a correlation between low levels of vitamin D and different types of hair loss including telogen effluvium, female androgenic alopecia, and alopecia areata. We also know that vitamin D receptors play a key role in starting the hair growth process.
Though this is a good baseline, we still do not understand vitamins D’s role in the hair cycle or how it contributes to hair loss. There was one study done showing that vitamin D may be useful for helping hair regenerate, which is a step in the right direction, but much more research is needed in order to determine the mechanism behind vitamin D’s interaction with hair and therefore no conclusions can be made.
Vitamin D in hair supplements
Until more research is available, you likely do not need to take vitamin D for your hair unless you are deficient, as it will not do much for you (again, based on current research). Many hair loss supplements and multivitamins include vitamin D more as a preventative measure for deficiency as opposed to something that will directly benefit your hair loss.
Again, if you suspect you are vitamin D deficient it is best to get a blood test done by your doctor to confirm it, and also to make sure there aren’t any other underlying health conditions that may be contributing to your deficiency.
The best way to ensure that you do not become deficient is by getting enough sunlight (at least 10-15 minutes a day) and maintain a healthy diet. If you do so you will likely get the needed 25-100 micrograms/day, which is what the mayo clinic suggests you intake to maintain healthy blood levels. Taking over 100 mcg can result in vitamin D toxicity and bring with it negative health effects.
There is a definite established connection between vitamin D and hair loss, and although scientists are beginning to understand it, there is much more research needed. If you suspect you are vitamin D deficient: get a test from your doctor to confirm it. Getting enough vitamin D whether it be through food, sunlight, or supplementation will likely help you improve your hairs condition and ensure you do not lose any hair due to deficiency.