Vitamins & Minerals
Individual Vitamins and Minerals
What are calcium, magnesium and vitamin D products?
Various combinations of calcium, magnesium and vitamin D are often found grouped together in products generally aimed at bone health, and whilst this is true, they also serve many other functions in the body.
Fortunately, if intake is at or moderately above the RDA level for calcium (800mg) and magnesium (300mg) then all of the health benefits can be expected to be delivered. Interestingly, in this regard, the USA RDA level for calcium was recently raised to be about 50% above the UK level, and so it would be prudent to view the UK RDA of 800mg to be the minimum intake level.
The exception is vitamin D where there is very strong scientific evidence accumulating that the RDA value of 5ug/day is too low to deliver all potential benefits and should probably be raised to 25ug per day for the UK population.
Who should take these supplements and what to look for?
Calcium and Magnesium
It is important that children through to adolescence receive sufficient calcium as this leads to an elevation in peak bone mass during adulthood. This in turn reduces risk of bone loss related disease (osteoporosis) later in life. Children should receive 1200mg calcium and 300mg magnesium per day from 3-18 years.
Most women over 15 and men over 18 would benefit from supplementing some calcium and magnesium into their diet. Depending on dietary intake look to supplementing 200-800mg per day of calcium and 100-200mg per day of magnesium.
Evidence is now strong that increasing calcium in pre-menopausal women to between 800-1200mg per day reduces risk of osteoporosis.
Women age 40 and upwards may find calcium supplementation particularly beneficial in helping to reduce bone mass loss and prevent osteoporosis. Again, daily intake from diet and supplementation should be between 800 - 1600mg per day. Magnesium may also be beneficial here in assisting with symptoms of menopause, but look to have an intake of 300mg per day.
Also, vegans and ethnic populations with low dairy intake tend to find it more difficult to obtain sufficient calcium from the diet and may benefit from supplementation.
Vitamin D
There is strong evidence that supplementation of vitamin D alongside calcium is essential for maximising benefits to bone health. In addition there is also very strong evidence building for vitamin D providing numerous additional benefits to our health. Moreover, although our bodies can make vitamin D from exposure of skin to prolonged sunlight, we tend to avoid this even when the climate allows! Similarly, we tend to get little natural vitamin D from our diet.
As such our vitamin D status is significantly lower than that which is now considered optimal and so supplementation of vitamin D is required by almost everyone. Levels of supplementation should be a minimum 100% of the RDA with optimal levels being about 25ug per day.
As a general guide calcium and vitamin D are priorities for bone health with magnesium a desirable addition for numerous functions within the body, and because multivitamin and mineral supplements do not typically contain RDA levels of this mineral. Vitamin D also has advantages outside of strictly bone health benefits, which require higher levels of supplementation.
| Nutrient | Typical Daily Supplementation Level | %RDA |
| Calcium | 400-1200mg/day | 50-150% (depending on dietary intake and lifestage) |
| Magnesium | 100-350mg/day | |
| Vitamin D | 5-25ug/day | 100-500% |
Can I take too much of these nutrients?
Under normal circumstances it is very difficult to take too much calcium or magnesium in the diet. The upper limit of long term intake of calcium which is considered totally safe is 2500mg per day which is considerably in excess of that which would normally be taken in either dietary or supplemental form.
Similarly, with magnesium, as long as directions on use of supplements are followed, the likelihood of taking too much of this mineral is virtually zero.