It’s one of the most frequent health premises — that a quick walk in the early morning sun is sufficient to strengthen your bones and elevate your vitamin D levels. However, experts raise the point that this widely held belief might be false. The timing of your sun exposure is absolutely crucial for calcium absorption and bone health — and according to the research, it is actually the afternoon sun that has the most beneficial effect, not the morning one.

The Science Behind Sunlight and Calcium Absorption
Calcium and vitamin D are the two main factors that build and keep bones strong. While calcium is obtained through eating, vitamin D is a must for its absorption in the intestine. If vitamin D is lacking, bone loss can’t be prevented even by a calcium-rich diet.

The skin produces vitamin D by itself when it is exposed to ultraviolet B (UVB) rays from the sun. The vitamin D produced then serves as a helper of the body in calcium absorption. But, here is the catch — the time when UVB rays that lead to the creation of vitamin D are most prevalent is between 12 p.m. and 3 p.m.

Morning sunlight is mostly made up of UVA rays, which do not stimulate vitamin D production in the skin. Early morning sunlight being enough is a myth. To produce vitamin D, the body requires UVB rays, which come from the sun at noon.”

Therefore, if your intention is to get some sun in the morning, you might as well be losing out on the vital time when vitamin D production takes place.

How Much Sunlight Is Enough?
Advice on exposure is always to be in moderate weather, i.e. a round 20 to 30 minutes of the exposed arms, face, and legs without SPF, two or three times a week is recommended. Usually, it is enough for the body to have a healthy level of vitamin D. However, long and unprotected exposure to very hot sun will increase the risk of sunburn and, in some cases, skin cancer or damage more than that one in a lifetime are possible.

“Balance is what matters most,” the medic quotes. “Being in the right type of sunlight for a couple of minutes is good for the body, but overexposure is never to be recommended.”

Why This Matters More for Women
Osteoporosis is the main reason of bone trouble, which is more frequent in women especially after the age of menopause. However, in recent years, the condition of vitamin D insufficiency and early bone loss has been detected in young women as well. A lack of physical activity, an indoor lifestyle, a bad diet, and a little bit of exposure to sunlight are mainly responsible for this phenomenon.

“In the case of younger adults, lack of vitamin D leads to osteomalacia — a condition that softens and makes the bones fragile,” says the orthopedic expert. “In elderly people, this changes to osteoporosis. The trend we see is that it is the IT workers and urban women who spend most of their times indoors that are affected the most.”

Supplements Aren’t Always the Solution
Although vitamin D and calcium supplements are quite easy to obtain, experts are against self-medicating. "Vitamin D alone is not enough; it has to be with calcium," the doctor suggests. "It's definitely better to have your levels tested and take supplements under a doctor's supervision."

The Takeaway
Perhaps it is time to change your plans if you have aimed to get your bones the daily dose of vitamin D by catching the morning sun. It is actually under the sun at its hottest hours, that is from 12 p.m. to 3 p.m., when your skin is most efficient in producing vitamin D, the key for
calcium absorption and strong bones.

One of the easiest and most reliable methods to prevent your bones from giving in to premature wear and tear is to expose yourself briefly and safely to the afternoon sunlight while being on a well-balanced diet and taking regular physical exercise. Therefore, if you are going to your daily "dose of sunshine," make sure you are doing it when the sun is really cooperating with ‍‌‍‍‌‍‌‍‍‌you.