Why add vitamin D3 if I already try to spend time in the sun? — Calcium+D3, food supplement, N90- VitalHarmony

Vitamin D is synthesised in the skin under the influence of ultraviolet B (UVB) rays. Regular time outdoors might seem enough to prevent a deficiency. In practice, however, the picture is more complicated.

Vitamin D synthesis depends on the angle of the sun’s rays: in countries with a temperate and northern climate (including most of Europe) from October to March the sun stays too low, and UVB rays barely reach the earth’s surface. Even on sunny days in this period, the skin produces almost no vitamin D.

In addition, synthesis is reduced by using sunscreen (SPF 15 blocks up to 93% of UVB), through glass (a car or office window), in people with darker skin, and with age, as older skin produces vitamin D less efficiently.

In VitalHarmony Calcium + D3, vitamin D3 (cholecalciferol) has a specific role: it helps calcium absorption in the intestine. Without an adequate level of D3, calcium from food and supplements is absorbed much less well — which is why these two components are so often combined in one formula.

If you already take a separate vitamin D supplement or a multivitamin, take the total daily dose into account so as not to exceed the recommended amounts. If in doubt, consult a specialist.