Bone Density vs Bone Quality

A recent article in a well known UK daily paper has stated "A balanced diet rich in a wide range of vegetables and fruit will, according to the experts, provide all the vitamins and minerals the body needs to function. Popping supplements used to be thought a waste of time, however a well known scientist has now advocated that as we spend far more time indoors than our parents did,  plus we have been led to believe that the sun exposure causes skin cancer, many people fail to realise that sunlight is our primary source of Vitamin D3".

 Whilst the alternative source of Vitamin D3 will always be via our diet: oily fish, fortified margarines, breakfast cereals, red meat, egg yolk, cheese and powdered milk for example, the usual advice is to obtain 10 to 15 minutes sun exposure to arms, hands or back. Longer exposures does not  provide additional benefit. SPF8 sunscreen reduces Vitamin D production in the skin by 95%, while SPF15 reduces it by 99%. 

 We can only make Vitamin D3 when the UV index is greater than 3, which in the UK is only achieved on some days in spring and summer.

 In the UK the recommended daily amount used to be 200iu per day however it has now been suggested that we should take 2,000iu of Vitamin D3 a day. Our northern climate here in the UK means that millions of us are now deficient, as dietary sources are not enough to keep levels in a healthy range.

 If I cannot get out in the sun for around ten to 15 minutes a day I take a supplement of liquid Vitamin D providing me with 2,500iu per day. This is in addition to calcium with magnesium supplement.  

 I understand  that it is impossible to overdose on Vitamin D3 (although the safe limits are believed to be 4,000iu per day), vitamin D3 is complex and excess amounts can be stored in fat and other tissues, it is difficult to determine how long a daily dose of vitamin D3 would stay in the body, but I've been told that large doses can stay in the body for two months - please correct me if I'm wrong!

 P.S. I've just read an article that states walking does not increase bone density (Google "does walking increase bone density")  whilst Pilates (in particular Clinical Pilates) definitely help to increase bone density for those of us with osteopenia or osteoporosis.  I walk a lot, go to the gym, attend Pilates classes once a week, take additional calcium with magnesium and vitamin D3 AND have six monthly injections of Prolia - due a DXA scan (previous t score -5.2) end of this month - results eagerily awaited!!