Pharmacist Blog: Vitamin “D-Lemma”

Welcome to another installment of our “Vita-gram!” This month, I wanted to write a little about Vitamin D, what it’s good for, and how to sift through the OTC options and find the best choice for you.      

Vitamin D is a fat-soluble vitamin and is absorbed through the skin from sunlight or through a diet of fatty fish (such as salmon) and fortified foods (such as milk and cereal). Few people get enough vitamin D from these sources and many need to supplement, especially the elderly population. Way back when I was a pharmacy student learning about vitamins and supplements, vitamin D was taught as the vitamin necessary for bones to absorb calcium. Within the last 20 years, however, it has become so much more, including playing a potential role in immune function and heart disease.

Vitamin D Supplements

Vitamin D supplements are available as vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). Both are converted in the body to the active form (calcitriol) which regulates calcium absorption in the intestines, although D3 is better absorbed and able to raise levels more than D2. Without enough vitamin D, the intestines cannot effectively absorb calcium, which causes calcium to leach from the bones to serve necessary functions in the heart and nervous system.

Vitamin D3 is available over the counter or paired with Calcium, Magnesium, and most recently, Vitamin K2. The Vitamin D3+K2 pairing sparked my interest, so I wanted to dive a little deeper into why these two vitamins go together and what population this combination may be a good choice for. Vitamin K can be subdivided into K1, which is found in green leafy vegetables and promotes blood clotting, and K2, which is found in fermented foods and promotes the mobilization of calcium. Vitamin K2 has two essential actions: activating the enzyme that incorporates calcium into bone and activating the enzyme that keeps calcium from sticking to the walls of the blood vessels.

Vitamin K2

Numerous studies have been published since 2004 documenting the effectiveness of vitamin K2 in reducing arterial calcification, reducing cardiovascular risk, promoting cardiovascular health, protecting against vertebral bone loss, and increasing bone mineral density and bone strength. Most of the studies have used MenaQ7 (MK-7) as the form of vitamin K2, which we carry here at Oswald’s in our D3+K2 from Ortho Molecular. In my opinion, this is a great choice for cardiovascular, bone, and immune health based on the available research, and most individuals can take it in place of plain vitamin D3. Although vitamin K2 has not been shown to affect blood clotting, I would still avoid this supplement if you are taking a Vitamin K antagonist, such as warfarin, or if you have a clotting disorder, and always speak with your physician before starting a supplement if you have acute or chronic medical conditions. ꝶ