This product boosted my vitamin D to a level of 45 with just a couple of drops in the morning. I bought this product because bio experts like Ben Greenfield stressed importance of bioavailability of supplements. Starting with a physical in 2012, my levels went from ~18 to as high as 28 (30 is the lowest acceptable level) with high doses of traditional Vitamin D pills. I began using this product in late 2018 and my Vitamin D was boosted 250%. Pretty remarkable. Yes, it's more expensive. However, clearly much more effective with much, much lower doses.

My wife has Lyme Disease and proper vitamin D levels are critical. We have used several brands and this one seems to be the most effective. The latest tests show optimal vitamin D levels for the first time. Administration of the product is easy. One pump under the tongue and done. Highly recommend.

Until a few days ago I really loved this product and had it on subscribe and save. Unfortunately, earlier this week I opened a new bottle, squirted it under my tongue as usual, and immediately spat it back out. It tasted nothing like it normally does and it was BRIGHT orange. Thinking that perhaps that bottle was just off I opened the most recent new bottle and had the same issue.<br /><br />Obviously something was wrong with the batch - they both have the same batch ID and are well within the expiration date. Hoping that it was just a batch issue I looked up the company and emailed them to let them know and as them for help rectifying the issue. I wasn’t asking for a refund - I can get that from Amazon - but I was concerned that the batch was bad and wanted to see if they could replace my two and let them know that something was wrong. I received a reply the next day that did not address my concerns and simply told me to contact Amazon.<br /><br />The lack of accountability for a batch that was potentially mixed wrong - which could be harmful to people if they assume it’s supposed to taste awful - is what really worries me with this. I loved the product but now I will not be buying it again since I don’t feel I can trust their quality control.

I've lived in Alaska for over 20 years where there's very little sunlight for many months in the winter, making Vitamin D production a problem for many, including myself. Even when I took Vit D pills regularly, I still kept having low Vit D levels when my doctor would do lab work so I knew it was just an absorbency issue with the pills actually making it through digestive system and into the blood. Even though this supplement is pricey, it does the job! Under the tongue and I'm seeing my Vit D level get close to normal for the first time in I can't remember how long.

These sublingual drops really do the trick for Vitamin D levels! My doctor says she has rarely sees someone with such excellent levels. The K helps with absorption so you get even more bang for your buck. Although the orange zest flavor is pretty sharp and takes some getting used to, you start noticing it is refreshing and don't mind it so much in time.

Loved the reliable delivery pump system for the first few weeks, now the pump nozzle squirts out about the same amount out of the rim on the backside as the dose Intended out the front. Wasteful and messy. Very disappointed with delivery system but loved the product itself; flavor, absorbency and thickness was perfect. Not sure how to fix this delivery issue?