Vitamin D3 and Vitamin K2 - Partners in Health

A few facts, some interesting research and some myths about the benefits and effects of vitamin D3. Also the fascinating recent discovery of Vitamin K2 and how it does an amazing double-act with Vitamin D3.

It is generally well accepted that everyone benefits in some way from the consumption of vitamin D either through exposure to the sun or directly through diet and /or supplements. 

The general advice given by medical professionals and also some Alternative practitioners is to avoid sun exposure between 11 am and 3 pm and to plaster a minimum factor 30 sun cream onto your skin whenever under direct sunlight. 

It would surprise most people to know that conversely the best time to be out in the summer sun is around midday and either side of it by an hour or so. In fact a general rule of thumb on a clear sunny day is to check the approximate length of your shadow. If your shadow is shorter than your height that is the best time to benefit from exposure to the sun as beneficial UVB rays will be prevalent. Outside of this time harmful UVA rays prevail which are responsible for skin problems like melanoma. Obviously you must restrict your exposure time sensibly and make sure not to burn, especially if you have very fair skin. Also avoid sun exposure on misty or cloudy days as the damaging UVA rays are more abundant. It is also better to avoid too much time spent under glass which filters out UVB rays allowing the harmful UVA rays to get through. 

Outside of this time it is best to simply wear a hat and cover up rather than relying on sun creams as they obscure the healthy penetration of UVB rays which actually react with the cholesterol on your skin to form Vitamin D3 in your body. Interestingly, most vitamin D supplements are derived from lanolin which comes from sheep’s wool – this is where the same interaction has occurred with the UVB rays reacting with cholesterol in the sheep’s wool and thus effectively delivering ready made D3. 

When absorbing natural D3 from the sun as described it is important not to shower or bathe with soap or detergent for 48 hours because cholesterol is a lipid and is therefore fat soluble and will undo the potential benefits (naturally it is OK to use soap on areas not exposed to sunlight).

Whilst supplemental D3 delivers a healthy dose of calcium to your system, unfortunately  it is not very efficient at distributing it to all the right places in the body  and large doses of D3 can deposit unwanted calcium in the arteries, heart valve, aorta and even the kidneys - potentially as kidney stones.

 Fortunately nature has provided a miraculous partner to combat this effect -  Vitamin K2.

Also fat soluble, Vitamin K2 taken with Vitamin D3 safeguards any surplus calcium absorbed by directing it to all the areas where it is needed such as teeth and bones. In fact research has shown that Vitamin K2 even slowly clears out existing calcium already previously deposited in the arteries and relocates it in the bones and teeth – truly remarkable!

It is important to emphasise that the most effective form of K2 (there are nine versions) is MK7 as this one remains in your system for longer and is most effective at calcium clearance. It is available as small white tablets, is made from ‘natto’ (fermented soya beans) and is not expensive.

It is useful to know your Vitamin D levels in order to ascertain how much you need to supplement with and there is a simple blood spot test to establish this which can be obtained online at  and only costs £29 from an NHS laboratory.You may be successful in getting your GP to do a blood test but this is unlikely as they usually consider it to be unnecessary. If you do manage to get a local blood test it will probably cost you about £80. Your levels should ideally be between 40 – 60 ng/ml (100 – 150 nmol/L). Typically most of the population in the western hemisphere will fall below these levels particularly in the winter months and will need to supplement with vitamin D3. 

Depending on your blood levels most people will benefit from taking 5000 iu’s to 10000 iu’s of Vitamin D3 daily and at least 200 mcg of Vitamin K2. These should ideally be taken together with fat containing food.

K2 and D3  work together to increase MGP, or Matrix GLA Protein, which is the protein that is responsible for protecting your blood vessels from calcification. In fact, MGP is so important that it can be used as a laboratory measure of your vascular and cardiac status.

The results of human clinical studies suggest that concurrent use of vitamin K2 and vitamin D may substantially reduce bone loss. Huge implications here for osteoporosis prevention and reversal especially during the menopause.