Taking vitamin D every day increases your chances of surviving cancer

Increased Survival: Taking a small daily dose of vitamin D in cancer patients can reduce their risk of dying, a meta-study has found. The mortality of cancer patients fell by an average of twelve percent as a result of taking the vitamin. The effect is particularly pronounced in older people and in people who have been shown to have a vitamin D deficiency. In contrast, high doses of vitamin D administered once a month had no significant effect.

Vitamin D strengthens bones, protects against infections and supports the nervous and muscular systems. A deficiency can lead to rickets and osteoporosis and possibly also promote dementia. Normally, our body produces enough of it itself, because the vitamin is formed from a precursor molecule in the skin when it is exposed to sunlight. But especially older people and cancer patients often suffer from a vitamin D deficiency.

Role of vitamin D in cancer controversial

It is disputed, however, whether the “sun vitamin” can also protect against cancer – or at least alleviate the consequences of cancer. While some studies have found a mildly protective effect in some types of cancer, others have found no significant effect. In the meantime, however, the preventive effect seems rather questionable: “According to the current study situation, taking vitamin D3 probably does not protect against developing cancer,” explains senior author Ben Schöttker from the German Cancer Research Center.

The situation is even more unclear when it comes to cancer mortality – the risk of dying from a tumor. “Previous studies on cancer mortality have delivered very different results and we are interested in the reasons for this,” says Schöttker. “By re-evaluating all previous studies on the subject, we wanted to contribute to arriving at reliable results on this issue, which is so relevant to public health .”

Mortality reduced by 12 percent

For their meta-analysis, Schöttker, first author Sabine Kuznia and their colleagues evaluated 14 clinical studies with a total of almost 105,000 cancer patients in which vitamin D intake was compared to a placebo. The patients had either received a lower daily dose of the vitamin of 40 to 4,000 international units (IU) or a high single dose of 60,000 to 120,000 IU once a month.

The result: A comparison of all variants of vitamin D administration with the placebo group showed no significant effect. The vitamin only reduced cancer mortality by around six percent. This is different, however, if one takes the mode of administration into account: in cancer patients who took vitamin D daily, there was a statistically significant reduction in cancer mortality of twelve percent. In contrast, the monthly high single doses showed no effect on cancer mortality.

Especially useful for people with vitamin deficiencies and for the elderly

According to Schöttker and his team, this result proves that cancer patients can benefit from vitamin D intake and that this can increase their chances of survival – if the vitamin D is taken daily. The researchers explain the better effectiveness of the daily vitamin D3 doses by the more regular bioavailability of the active ingredient.

More detailed analysis also revealed that the positive effect is even greater when those affected are older than 70 years or previously actually suffered from a vitamin D deficiency. “We observed this 12 percent reduction in cancer mortality after untargeted vitamin D3 administration to people with and without vitamin D deficiency. We can therefore assume that the effect is significantly higher for those people who actually have a vitamin D deficiency,” says Schöttker.

“This work underlines the great potential of vitamin D3 administration in the prevention of cancer deaths,” says co-author Hermann Brenner from the DKFZ. “Regular intake in low doses is associated with almost negligible risk and very low costs.” However, experts strongly advise against the dose of the vitamin. Studies show that this can have negative consequences, especially for older people, including an increased risk of falls and broken bones. (Aging Research Reviews, 2023; doi:10.1016/j.arr.2023.101923)

Source: German Cancer Research Center