Should I take Vitamin D with K2?

Or just Vitamin D?

Good afternoon everyone,

It’s that time of the year when taking your Vitamin D becomes very important. If you live in an area with autumn and winter months, taking Vitamin D is advisable. This is both for our immune health and for our PCOS. Women with PCOS are known to have low Vitamin D levels.

Recently, we have seen a rise in the combination of Vitamin D with K2 in supplementation. Let’s deep-dive and see whether you should take Vitamin D alone or in combination with K2?

Vitamin K

Vitamin K is a group of fat-soluble vitamins. There are essentially two: Vitamin K1 and Vitamin K2:

• Vitamin K1 (phylloquinone): Found mainly in green leafy vegetables and some plant oils - this is the primary dietary form

• Vitamin K2 (menaquinones): Found in some animal and fermented foods and produced by bacteria in the gut

They both perform very important roles in the body, primarily in blood formation and bone health:

1. For blood: Enables the production of proteins needed for blood clotting, preventing excessive bleeding when there is an injury - this is why babies will get a Vitamin K injection when they are born to ensure they are clotting well

2. For bones: it activates bone-building proteins like osteocalcin

Why Vitamin K with Vitamin D?

Both vitamins play a key role in Calcium metabolism. (I know, another mineral in the mix). Vitamin D helps calcium be absorbed from the gut, while vitamin K, especially K2, ensures that calcium is directed to bones and teeth rather than deposited in arteries or soft tissues. Vitamin K is like a bus driver for Calcium.

Of course, your body will also use the Vitamin D and K2 for other functions. You have probably noticed how much these little guys do in our bodies. This is why supplementing is not a targeted treatment.

Who should take this combination?

1. Perimenopause/Menopausal Women

I recommend this supplementation usually to women in perimenopause/menopause. Bone density becomes problematic at this time in a woman’s life (primarily because of oestrogen), so ensuring that enough calcium makes its way to the bones is critical.

2. Concerns with cardiovascular health

In addition, those who might have a higher level of cholesterol (LDL) or a family history of CVD and are taking a Vitamin D supplement, might be worried of Calcium deposits in the veins. If these people are also NOT consuming enough plant-based food to get the right level of Vitamin K, this Vitamin D combination might be best.

However, if you are taking a normal dosage of 1000-2000UI Vitamin D during winter times and you are fairly young and in good health, a pure Vitamin D supplement is enough.

A word of caution with Vitamin K. The most significant interaction between vitamin K in supplements and medication is with blood thinners, especially warfarin and similar drugs. Vitamin K can counteract the effect of these medications by promoting blood clotting, making anticoagulants less effective and increasing the risk of blood clots if vitamin K intake changes suddenly. This applies to both vitamin K1 and K2. If you are on this medication, please don’t take a Vitamin K supplement.

I hope you found this helpful. The way I think about it is, Vitamin D + K for bone health and CVD worries, pure Vitamin D for general use and immune health. There is always nuance there, so if you have a particular concern, don’t hesitate to get in touch.

See you next Sunday,

Francesca